I don't feel like much of my vintage collection is "mine" yet. I've only owned most of my vintage collection for the past 5 or 6 years. The items have existed for like 100 years, so others have owned them much longer than I. I'm not worried as much about ruining value as I plan on keeping them and most are low grade anyway.
The cards I bought as a kid in the late 80s, however, I could see stamping those. I pulled them out of packs and feel they are more "mine". That make sense?
Neat topic, Paul, that I've often considered.
Rob