Re: hand rash
Norm, I had something on my feet that sounds like what you're describing. It wasn't so severe and didn't last as long, but it sounds similar.
I'm sure you've already had this suggestion from all the doctors, but jock itch cream and neosporin. I would generally alternate them daily.
I don't know of much from these motors that could cause this type of issue unless you're allergic to something. Solvents will do it, so if you're not careful with the gas and carb cleaner and brake cleaner maybe. Working with fiberglass can put you at risk for skin issues too. resins, acetone, even the fiberglass itself.
What kinds of things do you come into contact with at work?
Have they removed a sample for analysis yet? Seems like that might help them figure out what it is....