+1 on keeping it original, but only if the parts are rare or proprietary to the frame and bike model. Try to retain things that the frame will need to be rideable by the next owner(s) like special sized and configured seatposts or items with rare or harder to find threading (Swiss/French Threading). Same with Pantographed components which will be best off being left on the appropriate brand and model bike, instead of floating around unmounted for years in auction sites and display shelves, looking for the correct bike to land on.

Chombi