Assuming that VW never actually painted their engines gold, sounds like it's a replacement. The only company that I know of who designates their engines by colour are TES, they do a 'Gold' in both 1300cc and 1600cc.
@Barry76 success! Looks like the European beetles continued with the full range of engines, the American market went with the 1600 tp only. Yes your right it must be a TES engine. It's stamped AR so still a 1300 unless heads have been swapped at a later date.
Just checked the clutch and I've got less than 1mm to the rivots so will be swapping this out. Going to get the 3 piece kit. Just undecided on the flywheel atm.
Ordered up the tool to get the flywheel off which I'm waiting on, but managed to rig up a dial indicator to check end play. It's right on the upper limit according to my Bentley @ 0.15mm. Hopefully a thicker shim should sort it.