Last year, I picked up a 1928 Ruddertwin still sitting in the original box. Tags and all. Original location of sale and owners names written on the wooden box. The motor had probably been run a few times, but not much. I’m in the process of cleaning it up and will display at a few meets, and will get it running to be used carefully.
As much as it’s nice to look at, I’d get more satisfaction seeing it run.
I guess if something is absolutely brand new, than it might be nice to keep it that way (sort of like breaking the plastic off of a collectors item), but once it’s past that stage, then my vote is to use it!