High Foreigner,
I have copied/forwarded this frame's details and this link to Neil of 'My TI-Raleigh SB4059' to see if he can shed extra light on it.
It has the trademark rear stay top plates of an SBDU made frame, but they may have been incorporated into Lightweight division design by then - hence the Nottingham 'Worksop' frame number.
By the way, that translates as W - Nottingham Lightweight Division, B - February, 9 - 1989, 001689 - sequence frame number. All gleaned from Neil's excellent site.
So in answer to your OP - yes, definitely worth the bother, but at 65cm way too large for me!
Regards,
Robin.