I think max runout for the forks is .1mm (point one of a millimetre)
Have you placed a piece of flat glass across the fork legs to check for twist? It's important!
Your front axle should slide into place very easily at all stages of re-assembly, particularly when tightening the fork brace bolts.
Surely there must be a worn out thread for fork alignment here somewhere?
Proper alignment makes the difference between a bmw and a bmwobbleyou