MrTerminator - thanks 
arran - yeah I know what you mean about the eyes - I've not actually touched them so a little playing (along with adding eyebrows) should help a little
Some Guy - cheers, yeah just seen the 'tumour' like bit in the neck - it must have been somewhere I forgot to smooth off after playing 
The ear just needs some more bending to match the original ref but I have been working off multiple refs and some are not as pronounced as that so its just a case of guessing at what would be better.
Realistically I should actually go back to the base maya mesh and tweak the eye/ear sections and have a go at rescuplting from scratch. It would definitely help having the hair and beard blocked in on the mesh and added with quite a lot of lines/edgeloops as it would mean that I could get a lot more detail in those areas. Maybe a play with subdiv patches before importing into mudbox might be the way...
Si