Why? Are you planning to do customizations? I've done custom work to "historic" pieces and the only reason I do is if it is a common piece or if the original is damaged. It also depends on the nature of your collection. I once collected for the "historic" reasons (the original figures, original equipment, etc.) but now it is for my own purposes. Some of the extreme equipment - Mamba for example, does not fall within my current interests and while I currently have a few of these pieces, I'm likely to put them on Ebay.

Destroying history is a personal perspective. Each of these toys have a story and they belong to their own legacy of time, but they are also toys to be played with and enjoyed. If the toy is incomplete or otherwise damaged; Do you want to restore it? Do you want to experiment with it and try building something new?

History is a perspective. How strongly do you feel that you would be destroying History?