So besides the leather for the polisher, the changed lines are "path" and "file"?
I'm considering putting those in the og ceramos patch manually to see if it works.

edit: Your patch works, but I had to add its changes manually to ceramos own patch. It's not throwing the vendor error anymore, and I could craft the polisher just fine! I hope you can figure out how to make your patch work, but in the meanwhile this is better for me, so I can have less mods in an already too big list :) Thank you for this!

Yeah that is in the original Ceramos. I just ran a correct patch after. I wasn't able to (haven't learned how yet) to get my patch to fix the patch.json in Ceramos before it runs. I just pulled the code, made the fix, and included it in the ceramospolisherfix.json

Seems like the trader still throws an error.

29.12.2024 09:01:18 [Error] Patch 0 (target: game:entities/humanoid/trader-buildmaterials.json) in ceramos:patches/trader-buildmaterials.json failed because supplied path /attributes/tradeProps/selling/list/- is invalid: The json path /attributes/tradeProps/selling/list/- was not found. Could traverse until /attributes/tradeProps, but then 'selling' does not exist. Full json at this path: {
"money": {
"avg": 30,
"var": 10
}
}