Rusty frame numbers = original paint(?)

[bmwdean]

On the slash-2 bulletin board recently, one person (John) posted the following in response to a previous person asking for help in identifying original paint on an R27. The former individual posted:

If its a re-paint (at least the frame)the frame number stamped on the steering neck will be covered with paint. From the factory it will be stamped after the paint job and usually by now the numbers will be slightly rusty and clearly stamped after the fact. If the frame number is covered with paint its repainted.
John

So I checked my Dominican blue R50/2 and black R60/2 and found, as expected, that both had "rusty" numbers.

How reliable might John's post above be?

http://motos.home.att.net/numbers.htm

http://jeff.dean.home.att.net/slash2.htm

[20774]

The numbers on my '69 R69S are stamped but the whole strip, from the top of the steering stem down to the first weld, is rusted with the numbers stamped into that strip. The BMW roundels are there on either side, but it's almost like something has been rubbing the area. There's a part of the wiring loom that hangs down in that area but it's not rubbed through as if it had scrapped the paint off the frame. I don't think these are forged numbers...I'm fourth owner so I can't be sure. But the engine, steering stem name plate, and the numbers stamped into the side of the frame all agree.

Kurt in S.A.

[CTHalk]

If the numbers are covered with paint, I'd be fairly sure it was painted post-factory after the numbers were stamped at BMW. My original R69S has rust in the numbers. Of course, after a frame has been repainted, it is possible that the paint was removed with a sharp needle or other tool. I doubt most painters would bother to do this, unless trying to pass it off as original paint.

[crazydrummerdude]

If the numbers are covered with paint, I'd be fairly sure it was painted post-factory after the numbers were stamped at BMW. My original R69S has rust in the numbers. Of course, after a frame has been repainted, it is possible that the paint was removed with a sharp needle or other tool. I doubt most painters would bother to do this, unless trying to pass it off as original paint.

I bet some people will do that now..

[woodnsteel]

Is this an un-refutable indicator?

[CTHalk]

As many states required a frame number to be visible during inspection, I am sure BMW would only stamp the numbers after the frame was painted. The numbers could be filled in and obscured by the paint if the frame number was painted after stamping. It makes sense that they would do it only one way, (rather than some painted before stamping, and some painted after). That would have gone against logical German facility planning....having two separate lines of material movement?! Does a 'rusty' ID number irrefutably indicate an original paint frame? Well, maybe only around the neck. The rest of the frame could be painted and 'blended' in to look original at the neck. This is only something that would be recent though. In the not too distant past, they weren't worth enough to take deceptive measures on to fool collectors. At least, that's my take on it.. I have found that on vintage motorcycles, the paint jobs were never that great from the factory. Ever seen an early seventies Ducati original paint job? Scary! I didn't know paint could go on so thin! Vintage Harleys? Can you say 'runs and sags'? Production motorcycles didn't get personal one-on-one attention from the painter like a restored bike gets today. Factory painters were working on volume! I have to say, I like the looks of original paint bikes because they don't look like the 'juicy wet looking' over-restored bikes all over the place today. Hal