Interesting. My TR2/3 SPC has 3 different ground straps listed. The Stanpart number was 501495 to TS18912, then 303006 to TS60000, then 509271 from TS60001 onwards (or at least until the end of where this book covers).
No idea what the differences were, but I see that TRF has the last one, 509271 cross referenced to the same Lucas P/N as the factory 131116 listed for TR4.
But the one that TS13371 is wearing matches Stig's description, so I'm pretty sure he's right about the TR4 part being usable on all the TR2-3.