Which is more valuable? Original or modern?
 

A Trek Tx770 with all original parts or a Trek tx770 with 9 speed Ultegra? I would think that the modern 9-speed Ultegra parts would outweigh the value of vintage cyclone parts, but I also know that things like powdercoating a frame can lower the value, even though it would be a stronger finish.
I'm half way through a conversion now. I'm just waiting on a smaller FD clamp. It's full Ultegra except for the Easton EA50's and I was just curious how it will affect the value.

Neither one sounds very vintage

are you planning on riding it or reselling it? if riding it, what does it matter? just do what works for you.

The PC will lower the value of the bike. The parts are a wash.

I modernize most of my keepers: put 9 spd DA on two of them, 9 spd Ultegra on a third. Did it because thats what I like to ride. For resale, those parts will come off. Kept the original decals and paint.

I'm keeping it, I was just curious how the value would be affected. If I were to sell it, the parts would come off unless it raised the value significantly.
I would keep the original decals and paint, but the decals are already gone and the paint is in pretty bad shape. It'll get a matching powdercoat and new decals when I can afford it.