The Q[uantum] pulley is part number 068121029A, the shims are 068121185B (4 or 5 will suffice) and the belt is 10x650.
I bashed my head quite a bit trying to make an OD 650mm belt work on my application. I am using a genuine 028 105 253A on the crank. AVX 10X660 seems to be the ticket for me.
Is there tool to hold the water pump pulley to allow tightening of the mounting bolts? VAG 1590 is too big.