There's little doubt that Hwe's track bike is a 1950s..possibly mid-50s British model...and quite a good one at that. All the equipment such as the Chater-Lea chainset and pedlas and the GB brakes are from that period.
The Nervex Pro lugs were used by just about every builder, so the only identifying features are such things as the top-eyes of the seat stays and the curved brake bridge..possibly the fork crown.
The long plated (or possibly solid insert ) top - eyes were fairly common, but as common as the double-fluted wrap-over ones. The curved brake bridge and reinforcement tangs are the mark of a quality frame as is the very attractively cut cast twin-plate fork crown. That's a distinctive design, but who's is it?
My guess is that it is either a ROTRAX or a GILLOTT. with the smart money being on the latter. I have several Gillotts and Rotraxes, but while both they have the flat top-eyes and the Rotraxs have curved bridges they do not have this type of reinforcement..but while they have twin-plate fork crowns, these are not decoratively cut...but the crowns on the Gillotts are fancy cut...but not in Hwe's pattern. Does that make any sense?
What does Mark, up there in Scotland think? Or does anyone put any money on the frame being a Holdsworth?
Nervex bottom brackets tended to have very sound if slightly harshly cut threads. The presnce of the sleeve unit is probably due to someone having either cross-threaded the bracket or wearing the threads away with a loose cup.
Norris Lockley. Settle UK