ACL are back up and running they were at the Auto Sports Show in 2015.
The UK importer switched to King as an alternative as ACL had been in administration for nearly two years hilst they were looking for a buyer, then they ceased trading/production, then eventually restarted.
The UK imported sorted out most of the European stock, which bearings were needed for what engines.
Many companies have ACL listed but do not have any stock or have old stock.
Male Motorsport are available for the YB in most sizes including standard, they have always been more money.
You should not be moaning about paying an extra £80-£100 for better specification bearings for an engine build which will cost several thousands of pounds.
I have had communication back from Mahle explaining that their Motor Sport range of bearings is available and production of their general grange of bearing should be back in production within the next two months.

Steve