If this has been posted by anyone else then apologies - I must have missed it but I know that the question has been much asked.
Following Dave's pointer last week to the Lawson offer on Bosch PMF180 blades I thought I would order a few to try with the Fein. I can report that the Bosch blades do indeed fit the old style Multimaster and work just fine.
They do not seem to be as well made as the Fein blades but at the p;rice who cares. Seem ideal as sacrificial blades where using them will almost certainly damage them - as I always seem to do when cutting skirting that is nailed to the wall where it seems impossible to cut cleanly through the skirting without damaging the blade on the brick.
Andrew