Having had a foot in both worlds over the last few decades, I have a lot of thoughts on the matter, but will spare y'all most of them. An original and rather presentable car from the 30's-60's should stay that way. You'll often get points for that at a show. (Beyond the 30's, it ain't likely to happen.) I have restored a few ratty 50's-60's British roadsters that would have otherwise be part of a Kenmore washing machine by now, thus saving them for posterity. Likewise, a gun will tell you if it needs 'restoration'. Egregious damage should be addressed and I see nothing wrong with replacing modern parts/Bubba additions with period correct parts. One last thought. If Kermit Roosevelt's African safari rifle turned up in deplorable rusty/rotted condition, then of course a full restoration is called for. Not so much for Uncle Joe's Savage lever gun that he carried while prospecting in the Yukon.