You're probably right. I think if they are rust free to it helps .
Rust free examples plain don't depreciate, at least not in the last few years. I really lucked out when I bought mine - and at the time I felt like I was overpaying. I've been offered $2500-$4000
over what I paid for mine quite a few times. A friend from the club recently sold his 320K 1990 that needed some attention to a few things for $3500 in one day - and I bet he could have got more had he been a bit more patient.