Hofferwood, if my understanding of the Wright date codes is correct, that breaker would be a 1981 with the U.
I'm sorry BM I don't know when it was disco'd. I will try calling Wright and see if they have anything to say, I don't have any cat scans I'd never looked to be honest lol. I did notice this rat doesn't say USA, neither does my 3428.
I had a 4400 1/2 dr. but I gave it to my dad because he likes them. I've just collected the 3/8 so far.