[oem4me]

Nice Sub. As for the question of restore vs preserve, the latter is always my first choice. That is, if there is enough originality there to warrant it. Broken stuff, heavy rust, previous repaints, etc., dictate a different approach.
The appeal of originality is simple: It's all about CONDITION. Something old that has honestly and obviously avoided ruin is rare and special. On occasion, there are things that are mostly well preserved but show some form of damage requiring repair. I say there is no harm in letting the repair show, just as honestly as the surrounding originality.
For example: Picture an art museum featuring pieces from antiquity, as in ancient stone carvings and statues and such. These pieces of art are seldom without some form of damage or loss. The missing bits are either left as-is, or if needed to complete the form, they are re-created in a material that lightly contrasts with the original. The added bits serve a purpose, but no effort is made to conceal their presence. Absolutely zero is dishonest or fraudulent about that.
Now, fine art and cars don't compare as for what they mean about the human experience, but the idea of being truthful about condition is the same.