Being somewhat of a stickler for detail when it comes to building up a classic bike, I can't help but notice the number of frames being offered for sale with reproduction decals that are incorrect and in some cases downright fraudulent.
I tend to spend quite a bit of time researching potential buys (sad I know), but prefer to see a few scratches and faded decals rather than shiny looking paint on a 20/30yr frameset.
Although I would probably not spend more than a few hundred quid on a good steel frame, it would be frustrating to get a plain gauge donkey of a frame when you thought you were buying a 753 lightweight cheetah.
So far I haven't bought a donkey but I'm sure some have.
I think you have to do the best you can. A few examples from my own fleet.
Carlton Flyer - bought as a near basket case, repainted with correct decals, fine.
60's Geoffrey Butler and 60's Mercian - both have their correct decals and paint jobs at the moment, but both need repainting, the Mercian especially, and I can't get exactly the right decals, so I will do the best I can.
My day to day 80's 531 Raleigh, badged as a Rourke, and with 653 decals. I bough it like this, and paid a very reasonable price, but it isn't what it says it is - it's a pro respray, so the incorrect tubing decals are a little naughty, whoever did them. It rides brilliantly though.
The truth is that a lot of classic frames have paintwork that is too far gone to realistically save, and much as I'd like to keep them original, if it has rust, it needs painting. Waxing etc will only keep rust at bay for a while.