Never heard of an early an late mk3 alternator mount? The mk3 and mk4 mounts are similar but different, with the mk4 mount dropping the alternator a few centimeters more. These can be identified by the fact that the mk4 mount has the support attached to the mount, where as the mk3 mount has the support bar attached to the block.

For PAS, I'm just using the US Escort rack form 1987. Mind tough that mine is a standard and standard LHD.