I think it has been part of the hotrod scene since the 50's. I like the home built aspect the best.
Absolutely correct. The cars I grew up seeing and trying to build myself were what we would call rats today. Some people say that all hot rods in the 50's and 60's were painted and finished nicely..........not in my neighborhood. Maybe we didn't have the money the guys in Southern California had, but we pretty much built them from whatever we could get cheap or free. When you are making 80 cents an hour it's hard to have an expensive hot rod and still manage to pay for dates, food, gas, etc.
The very first hot rod I saw in person was in about 1957 when our school band bus stopped at an ice cream place after a football game. While all the other kids were eating I was drooling over a 36 Ford coupe sitting there. It had no fenders or hood, a flathead with one carb and a chrome air cleaner, side exhaust made from bendable tubing and chrome motorcycle muffers, and red wheels and wide whites. The car was in gray primer and was far from the ones you saw in the little books, but to my eyes it was perfect.
Most of the cars that young guys were building back then were like that. There was one "older guy" (probably in his 30's

) who had a channeled, fenderless 32 roadster that was painted red and finished pretty well, but he was a machinist and had the skills and money to build one to that level.
The names may have changed, some called them jalopies, but today they would be called rats for sure.
Don