I don't really know why. I just thought it might be nice to keep as much of the original as possible. It also seemed to be important to marque experts that as many original features as possible are retained. Almost every buyers guide I read, albeit after the event, made much of a car having the original front fenders, spot welds etc, and that all body numbers match. I don't see it as any different with something like this. That being said I am thinking of a colour change, but I think if it is done right that shouldn't really affect the cars integrity or value.
I guess a lot of it depends on what I find after the suspension is removed and the underside is cleaned and inspected. If I wind up replacing all the floor pans then there won't be much of the original left, in which case I will scrape it all off so that it all matches, if there looks to be any issues there then again I'll remove it all and start again, but if it all looks perfect then I don't really see the point in disturbing it and making extra work for myself.
I think really I need to play it by ear on this one, the intention at the moment is to leave it be, but that can change in a heartbeat, it was never my intention to replace the fuel tank but it turns out I'm going to have to, nature of the beast with old cars I guess.
I don't know, maybe I am being a bit silly about it and the right thing to do is to get it all off and see what is there. Watch this space!