>>96233402
Inventor or alchemist are easy picks for class depending on how you spin it. Forensic investigator could also probably work.

For dedications, Lepidstadt Surgeon can be fun and have a lot of flavour if they have a mad-science kind of feel. Maybe eldritch researcher. Maybe scrounger. Hard to really use those for a dm pc though I'd say.

I'd say you'll have a better time just making a purpose-built NPC but I've done the same as you to ok results before.