Jerry,
Dating a frame by it's tubing decal can be a problem because a frame can be made much later then when the tubing was bought which can also be a long time from when it was manufactured. In addition, decals can get separated from the parent tubing, thrown in a drawer and used when needed. This is especially true for smaller companies.
In the old days, when Columbus was mostly just SL or SP, I would ask the customer if they wanted the tubing decal on the frame and, if they did, I would go to the file folder and find a Columbus one and stick it on (before clear coating). I would buy sets of Columbus tubing from all kinds of sources - frame companies that had gone out of business, whatever - and this tubing could have been sitting around a long time before I got my hands on it and still longer until it was made. When I got the tubing, I would take the decals out, plop them into the file folder for them to await the day when someone actually wanted one on a frame. Most customers didn't. You get the picture. Something not related to just-in-time inventory control. Of course Eisentraut was/is a bigger operation so decals would be used in more timely way but I think the possibility of the lag time described still exists.
Doug Fattic
Niles, Michigan