Oil heat exchanger fittings (HELP!)

Dear all

I've the dreaded slow leak of coolant into the oil (think mayo on the dipstick/filler cap after even long runs and if sat cold, and slow loss of coolant). I've checked gases and don't think it's a head gasket. So I've picked up a Febi oil cooler body and aluminium heatsink (apologies to anyone offended by my lack of using VW parts!).

However, whether buying VW or not, the cooler heat exchanger doesn't come with any fittings. It takes 5x bolts direct into the engine block but no matter where I look/phone, I can't seem to find anyone who can identify what bolts I need before I take the cooler off (which I don't want to do until I have the fittings!). They're torque+90 degree twist so they are single use bolts.

Please could anyone advise on what x5 bolts I need for a DFHA 2.0 140/190 engine's oil heat exchanger body to crankcase?