Ok, found somewhere stateside that can supply upto 85amp alternators for T1 engines, with the following part number
ALTERNATOR, NEW, 12 VOLT, 85AMP BOSCH AL82X ALU
042 903 023C
They also offer it in chrome (not for me thanks).
Have also found companies that can rewind it for upto 95amps...
Just waiting on a callback from someone that should be able to help me with what I am after.
Thanks,
Sam C