As odd as it sounds, I feel like this is probably playable in a Goblins shell. I know few folks have tried out Grixis Gobs, but the only substantial weak point of the deck is that it's full of tiny Goblins who can't do combat. Since you run Tinker and Welder anyways, this turns a graveyard full of dorks into 4/4s with substantial ETB triggers. Not claiming Gobs is viable with so many Ballistas around, but this is the Tinker target Gobs has been looking for. Huge upgrade to the deck.

This may also be viable in various shops builds, too. Ravager and Ballista are cute with a 4/4 base.

You manage to resolve Tinker and this is the artifact you want to cheat into play?

Usually you go for Memory Jar, Trinisphere, grave hate, or Wurmcoil. This is arguably better than Wurmcoil since it also produces infi bodies, but doesn't itself die to StP.

How does it even produce "infinite bodies"?

I think the best thing this does is transform Tinker into a reanimation spell to bring a 4/4 Griselbrand into play.

It produces incremental advantage (infinite guys) over multiple turns. I'm still not seeing how this effect is worth 7 mana though. It's less impactful (by a mile) than Blightsteel Colossus, less resilient than Wurmcoil Engine, and less explosive than Memory Jar. Not to mention that if you're playing this in a deck with Griselbrands and graveyard shenanigans, this card plays right into your opponent's graveyard hate, where a big advantage of Tinker is opening up an alternative path to victory.

Shops decks have better things to do with 7 mana, and blue decks with Tinker have more impactful or explosive targets for the second-most-busted spell of all time. I'm just not seeing it.

Does this let you get around Phage the Untouchable? That could be cute.

@Serracollector Nope, she'll still have the "from hand" clause and you'll die.

@AmbivalentDuck I feel like this all assumes that the Goblins shell itself is playable.

Have we considered splashing BW so we can play Debtor's Knell? It's harder to remove than this, since this get's Ingot Chewed and By Forced.

Turn 1 - Land, Skirk Prospector
Turn 2 - Land, Sacrifice Skirk Prospector, Goblin Warchief
Turn 3 - Land, Skirk Prospector, Mogg War Marshal, Brightstone Ritual for RRRR, sacrifice Mogg War Marshal and token buddies, cast God-Pharaoh's Gift, reanimate Mogg War Marshal during combat.
Turn 4 - Probably win.

And that's without power!

@Topical_Island Which is itself dubious. 2B Jester's Cap with a 5/3 body attached remains strong, but the cost of swinging with a Goblin or Rogue keeps going up. We haven't gotten a decent Gob in a while, though we do have some interesting Rogues. This is probably as bad as Gobs have been since the printing of Earwig Squad. Walking Ballista is a nightmare for a deck full of 1/1s.

One of the things that's hard to communicate to folks who aren't used to playing Gobs is how grindy most games are. Getting a 4/4 every-ish turn, often with a tutor attached, wins grindy games in ways that something vulnerable to StP and other spot removal wouldn't.