If I learned one thing from re-registering my car as a replica, it was that there seems to be a lot of leeway afforded to the DMV folks in doing a lot of stuff. The general thinking is "well, nobody else knows what the hell to do, so I'm gonna do it this way".
Their supervisors can often guide them into a posture where they won't all get into trouble and that's the direction they take and then figure, "nobody's gonna dig into this in the future anyway, and, if they do they'll never trace it back to me(us)".
Don't get me wrong - Everyone I've dealt with at various RMV/DMV offices in several states want to do the right thing, but there is often so much ambiguity in the rules (especially for a car like ours that they might see once every couple of years) that they end up doing the thing least likely to cause trouble down the road and I'm OK with that.