I may not correctly understand what you mean by rebuild? If you mean taking a shabby beat up piece of iron and cleaning/replacing broken or worn parts....I have a lot of respect for people who do that correctly. Less so for people who try to change the bike into something it was never intended to be style wise. To be clear, I'm not anti mods. But there are tasteful mods and there are garish ones. Then there are the ones where the builder has no effing idea of the impact of his mods on safety.
I specifically meant a registration with the bike listed as "Rebuild" as its status, meaning that at some point in its life, it was deemed to have more damage from an incident than the bike itself was worth. The question with a 40+ year old bike (a 1983 in my case) is exactly when did the bike experience this? When it was new and carried a high replacement value, or just a few years ago when a broken headlight could possibly be worth more than the whole motorcycle? Knowing this could help theorize the extent of the damage that caused ICBC to write it off.
Anyway, I was looking at a bike titled rebuilt by ICBC that otherwise looked quite good from having a recent clean-up, but ultimately decided to pass on the bike due to the status. It's definitely an albatross hanging around the neck of a vehicle, regardless of its condition today.