Knedert, the Ca. issued ID tag is nothing new as you probably well know. My nephew (and a little help from me), did a complete restoration on a 37 pickup that came from Ca. It had the Ca. ID tag on it and that was over 5 years ago since I first layed my hands on it.
It would have been nice if the previous owner could tell you who HE got it from.... and so on down the line. S.C. use to give you a title history for $5 bucks but that stopped sometime after I got my pickup in 1994 because I could get one back then.
Will Ca. give you a title history??? Doubtful.
Anyway, it looks like you got a good deal, it runs and will certainly serve you well. Good luck and I'm watching this mystery unfold like so many others.