I've sold at least 10, maybe 15 or so on Ebay with no complaints, only positive feedback:
https://www.ebay.com/itm/293012012749
The issue: the IIgs ROM 1 uses a soldered lead lithium battery. Why, Apple?!
This kit lets you clip the battery leads, press on two very tight fitting wires that won't slip off or short other things like alligator clips would, and the other end press fits onto a PRAM type 3.3V lithium battery holder you can mount where you like. Zip tie to power cable, tape, etc.
Lithium also probably won't leak ever, unlike those AA kits that are also much larger.
So:
No desoldering
No leaking
No potential shorts
No soldering
Mount where you like
I did this to solve all the things I didn't like, so, I'm not just the inventor, I'm a user.