[Gunner]

I'm not sure. Mine is titled in MA, but so far California has ignored that and is looking at it as a newly presented specially-constructed vehicle. Having the MA title has cut me no corners. Most importantly, I don't think I could bring in a MA vehicle registered (properly) as a 2006 and get an SB100 - for that, everything I've read and been reliably told indicates that you have to go through the process from scratch.

It's possible that a state with engine-year smog rules might accept the CA (or any other reliable state) title with no hassles.

I note that the California process has an out: if you can't prove ownership of all the parts, you can post some sort of vehicle bond against the day when your engine's owner shows up waving a pink slip. Or whatever. That might provide a loophole.