Welcome aboard. I too am an old and model builder who started around 1960. As a kid there was a bit of parts swapping going on. and kits were dirt cheap by today's prices. Like you I sold off at least one huge stash of parts in the midst of raising a family and needing some cash to make Christmas happen. No big regrets. The kids had Christmas but I do miss so many of those kept parts. Since coming into this forum I have had some unexpected joys to replace what I had for a long time known as loss. There are some very helpful souls out there. A cornucopia of help tips, and genuine appreciation for modeling. It is a great forum. I can now reignite an old nearly counted for loss project. Parts I can only imagine were sold off in one of those boxes of goodies have been sent to me and a dream that is now more than 50 years old is back on the table. And from one Marine to another...Semper Fidelis and welcome.
Poppy