Some R3 crankshaft gears have a dimple, some do not. It would be on a tooth of the gear if you've got one.
If you're just re-shimming stock cams, a rod in #1 will get you close enough... then look at your cam gear marks. Make sure you follow the instructions in the manual EXACTLY regarding loosing and tightening cam ladder! If you bend the cam ladder, you have to buy new head.
I have never used the Triumph cam tool, just used flat bar stock and screwdriver, but getting the cams back into position can be tricky. Probably easier with Triumph tool.
Modified piston stop for EXACT TDC
Precision degreeing of Cams (not necessary for stock cams)