The saga continues.
Testing of the head (M20 '88 525i e34 - 240,000 km) has revealed a crack which the reconditioner (reputable and highly recommended) thinks he can fix.
The head will also need 5 thou to be removed from parts of it as well as a new cam and rockers etc.
The alternative is a new head from BMA (Spanish) which will be dearer but will at least will not be repaired as long as the quality is OK.
Questions :
Can these heads be successfully repaired ?
If 5 thou is shaved off, do I need the thicker head gasket ? The reconditioner thinks not !
Has anyone any experience with the new Spanish heads at BMA ?
Any other advice ?

(Sorry to be such a pain but I am in unchartered territory here and am relying heavily on your collective wisdom ! )