Bartamos,
I think Jim Carter's universal 12volt switch has the thermal circuit breaker,located at the very rear of the switch mechanism,
http://www.oldchevytrucks.com/cart/product.asp?prodid=EL160&i=9764|||||
The breaker is held to the mechanism by the two bolts/leads you see at the very rear. I don't remember where I got the new circuit breaker itself, possibly from an electrical parts place,
Kent