B Group/WDB40

[DWS]

I am in the process of rebuilding the forks of my WD B40 and noticed that the fork damper tube socket screws had a sort of seal running length ways down a slot in threads.  I then came across a Service Sheet (thanks Julian) stating:

"To prevent oil leaks, fork damper tube socket screw No. 41-5138 is replaced by screw No. 97-2688.  The new part has a 'NyLoc' strip insert along the thread to prevent oil leaks".

Having searched for p/n 97-2688 on the Interweb I can't find anyone in the UK who lists this part, though one or two places list the older/original screw.  Does anyone know where they might get a couple of these later/modified screws?