Me, I gather all the parts can, I have two complete engines and transmissions, a box of carbs, a box of distributors, several complete exhausts, spare doors, spare windshield, brake boxes and boxes full of nuts, bolts clips, etc. It started when I bought the 65, the guy I bought it off had a 67 parts car, he had stripped it right down to the last bolt and clip - I got all those parts as part of the sale.
Now I cruise swapmeets and watch the trader forum looking for rare bargains. I'll also gather parts for LBCs I don't have, I found some Vandervell engine bearings for a Midget at a swap meet recently and grabbed them, I also have most of a Spitfire in boxes in the basement.