I saw this frame in the for sale section and thought I might throw my hat into the ring of guesses.

The features here aren’t unique enough to get a positive ID, so I’m just making a semi-educated guess.
On seeing the serial number, I thought that this could be a Witcomb (a UK built rather than a CT one). Serial numbers on Witcomb frames generally have the year as the last two digits and can be 6 or 7 digits long overall.

Witcomb were a bespoke shop that employed a number of builders over the decades they were located in Tanner’s Hill, Deptford, so their frames show a wide range of features. This makes it hard to pin things down.


Here are some pictures that will hopefully support the case for it being a Witcomb:


Serial/Frame Numbers:

Numbers were generally stamped across the bottom bracket. Also, I have yet to see a Witcomb number that was stamped in a perfectly straight line (like you’d see on a lot of mass produced Japanese frames, for example).

The numbering system would appear to be [sequential frame][yy] as numbers from the 60s seem to be mostly 6 digit and then growing to 7 digits by the early-mid 70s. However, this video bit about Witcomb:


has a scene (around 1:30) where Barry points to their ledger where you can see frame numbers from the last week of July 1973 that range from 1010673 to 1017073. Seems like a pretty wide range for 10 frames built in one week.

Anyways, here are some examples:

650569


650869?



954472




1027973



1122475





The ‘stalactite’ bit:






Use of Nervex lugs:

Most Nervex Pro built Witcombs I’ve seen didn’t have the ‘rib’ filed/trimmed but there are a few that did.





The circular cable guide use:




Fastback stays, sloping fork crowns, top tube cable guides, stay ends:




This one was allegedly made by Bill Philbrook: