Originally Posted by dwscrimshaw@bti

Yes, this has been giving us some thought too. I have kept it separate from the other shop frames for the time being until more info comes to light. Can't see why this would have 4 digits after the date unless there is some other system for team bikes, but I have not seen this suggested anywhere. All other shop frames of the period only have up to 3 Digits after the date although a number of these have been found with numbers far higher than the expected yearly volume of ~150. That said this figure was suggested for up to the 60's it could have increased after that, but again I have not found anything to support that other than these numbers.