This is how you wind up drag racing raiders on a turbo-charged lawn mower.
This relies on your familiarity with stuff that's shown - it works on things that actually exist now. You won't get this frisson with science-fiction gear, or at least, not nearly as much, because you're not combining existing material culture with a novel society, amputated from our own by the apocalypse. With science fiction items, you're asking the viewer (or imaginer) to envision two made-up things - the original group of folks that created the fictional gear, and the new group who have repurposed it.
However, I think Gabor Lux (among others) has shown another way to handle science fiction gear in a post apocalypse - make it strange and fantastical to the players, make it imply a culture quite different than anything we imagine.
And now I can't find this PDF on his dang blog!
Hah no wait, here's the OSR technology table I'm looking for.
So yeah, it has a very Carcosa vibe to it. Technology breaking rules (like lasers pinholing right through armor). Societies so far advanced that your AC is now obsolete. Technology for mind-controlling the masses and alleviating boredom.
So here's some additions I thought through.
Artifacts in the Wreckage of the Great Age
1. Fight enhance helm. Shows brain and central nervous system of enemies, if any, as well as anything central to circulation. So humans are a brain and the nerve cord in the spine, and a heart, and otherwise just a vague outline. Use knowledge and targeting aid to take 5e-style Advantage on damage rolls. After 4 uses the helm's working components fuse to your face. Your vision, brain are glitched and all you can see of other humans and humanoids is their brain and cns and heart, and a vague bodily outline. Good luck telling if someone is lying to you.
2. Parent Pod. Will accelerate time and raise a baby or child to the old age of majority (20.1). Kids will seem haughty, disadvantage on pleasant social interaction, but increased chance to identify tech or use it.
3. Mutantor bomb. Gives 1 mutation defect to anyone in a 100' radius. 15% chance of beneficial mutation. Emits no radiation. Modified mutantor bombs led to the current reality of mutated animals and humans running around - radiation was a side-effect of the subsequent Mutant Wars. 'Mutating radiation' typically means there's an unexploded but slow-leaking mutantor bomb nearby. (Weighs about 40lb, sizeable, bulky, but pack-mule-able.)
4. Moviedust. A tiny of powder. If a pinch is ingested, shows you the trailer, 1d6 rounds. If snorted you see the entire movie, 4d4 turns. You lie in a comatose state trembling. One hp of damage will rouse you, angrily, likely just before some interesting part of the plot. 2d4 doses.
5. Magma tube. Stone tube 3' in length, rather heavy, stoppered on one end with a hunk of metal. When removed, the tube oozes magma for 1 turn at the rate of 10' per minute.
6. Pain generator. Creates electricity based on local level of suffering and misery. Often used by slavers to power large barges of slaves who are whipped until their suffering becomes an insipid insanity. After which new sufferers are needed.
7. Floating barge. Think of Jabba the Hutt’s pleasure yacht. Slow, floats above the ground. Requires a ton of power to run. See: pain generator.
8. IndocChamber. Will kill mutants. Pure strain humans will receive some cybernetic augmentation (+1 to Str, Dex, +4 hp) and hypnotic conditioning. Will be compelled to uphold the law.
THE LAW: 1) Kill mutants. 2) Stop thieves! 3) Hang murderers. 4) Mutilate those who steal intellectual property. 5) Prevent riots, peasant uprisings, democratic systems. 6) Hunt down poachers (ie anyone who hunts at this point). NPCs obsessively act out their Law Compulsions, PCs get 500 xp for acting on them, but not if they're doing so in a really hypocritical way - ie hunting down some mutant while being aided by one in the party.
9. Repeller. Gnarled plassteel stick. Held in both hands, generates a bubble of armor energy, AC 2, AC 5 if moving. Large enough for 2 people to fit inside. If several people with Repellers are standing together the force shields are joined. Used for riot control alongside energy lances.
10. Energy Lance. Does damage as a laser pistol, can also make for a pike-like hand weapon. Long enough to stand behind someone with a repeller and poke the end out of the force field.
11. Indelible pen. Metal stylus with a very sharp point. Scratches out a thin black line onto anything, typically to a depth of 1". Does not bleed through paper somehow.
12. Kiy Novellas. Crystalline crowns which transport the wearer into an ongoing play for 1d4 hours. Depression, ennui, obsession follow. Save at +4 for 1d6 months. If you fail, the PC runs off in the night and becomes a murderous insane NPC. Play contents: 1) A woman berobed in gold, whispering to you, following you around, always over your shoulder 2) Dancers cavorting everywhere, hypnotically, while the world is frozen 3) Noble courts where all wear warped masks 4) Kaiju tentacle beast walks the world, devouring it
13. Gravity mace. Damage as a mace, targets must save or be flung back 15'.
14. Flame-retardant biological and radiation resistant Peace Observer uniform with hidden knives, contact poison hidden in indestructable ampoule in belt. Comes with a helm and a white, full-face mask which has a blank, inhuman expression. Grants advantage on rolls to resist radiation and chemical weapons, disadvantage on attack damage done by fire. Armor as leather.
15. Levitation spine. Replaces spine, Con -1 (requires a cyborger or a good automated surgical suite). Can levitate self at will if not heavily encumbered.
16. Grinder mouth. Replaces teeth, tongue, lower jaw, upper esophagus, same install requirements as levitation spine. Converts plastic, scrap metal, gasoline or hydrocarbons to nutrient paste. Works on regular food as well. You look normal if you don't smile. Loud in use. Thanks to Mutant Scavengers of the Ruined Earth's Termite Mask.
17. Last Act Pill. After ingestion, death of the eater of this pill generates a sizeable explosion: 8d8 damage to everything within 200', save for half. Undetectable except in stool samples.
18. God Botherer. Strapped to an object or person, they will be treated as a god. Reaction rolls determine if this is good or bad, but people will be scared to attack or debate with or contradict a god. If the user or object is injured, all present can save to see if they ignore the GB's effects.