Mine is late '50s. Could you post a picture of the dropouts on your grubb please? mine have a small potrusion where it appears that the deralieur hanger has been filed off, but I'm not certain. We could compare the dropouts where the derallieur attaches?
Cheers for the message about this :)
I'm at work at the moment, but I think I have a good idea as to which model I am riding. I will post the link when I get home...
In the mean time, here is a pic of my built up bike. The grubbs can be dated by the headbadge.
http://mc-nebula.com/bike/fixed/
Mine is late '50s. Could you post a picture of the dropouts on your grubb please? mine have a small potrusion where it appears that the deralieur hanger has been filed off, but I'm not certain. We could compare the dropouts where the derallieur attaches?
edit, also, what are your lugs like?