as the new set of cases came without nuts and bolts and the set from the old engine is rather knackered, new ones had to be sourced.
searching the internet, for instance: http://www.eBay
revealed some ridiculous pricing; 5/16 x 26TPI x 2,5"@ 1,20GBP each. P&P to be added.
local machineshop has the correct dies for 4 GBP and M8 (yes metric) has the correct shaft diameter.
improvement possible, I'll make a new set out of M8 allen-bolts