Is the topic here to watch when you sell things off, you might end up needing some of it? That's where I am now with selling. I think of my '67 project as built with parts I already have, and I do have most parts dedicated to both my trucks separated from parts I'd sell. But you never know everything you'll need till you get into the restoration. Also, although I've been saying I'm good with the two I have being my last, I don't trust myself. I do find myself getting ideas for other trucks still.
I see the word "hoarder" misused, tossed around too easily. At least in terms of the sickness. It's not sick, actually quite a smart thing, to gather items that relate to the vehicles you own and work on. Parts are easier to find now than 30 years ago. Back then, when you found certain parts you bought them or you may not find another. And you knew you could always resell it. And my parts stash isn't clutter. I have all parts stashed under roof and out of the way in it's place. I'm a 67-72 GM truck guy and always have been. Having a stash of parts has always been a part of that. The thought of not having spare parts just doesn't seem right. I am in reducing mode all over, but there will always be a minimum of parts I will retain, unless I end up getting away from these trucks. I don't believe that is even possible. It was even difficult for me to type that!