Thanks so much Gilles. Modifying these adapters is turning into a bit of a rabbit hole now and I like to move along, so I guess I'll cough up and get some adapters ordered.
My fittings are not stainless steel, running the saw through was far easier than stainless and even easier than regular iron / steel would be. Also the goldish color suggest it is more related to brass. Still that can be welded, but not trivial at all. So really happy for you that you found a good welder who didn't even ask questions ;-)
As for fittings there are three types available in Europe (all in the UK unfortunately);
Aluminum ones, using the Porsche style O-rings. Look fine quality wise
Same shape, but zinc coated steel. The finish does look a bit rough (lathe rings at the 37deg sealing section)
Or stainless steel ones using a different double O-ring sealing. Finish looks good.
The adapter at the hose end is going to be either steel or stainless steel.
Any recommendations? I am leaning towards the stainless ones.., but open for input
[Edit]
Looking in more detail, the stainless steel ones have both lines going to AN6. The JIC fittings I can get allow up to 3/8" hose. Porsche actually uses 1/2" and in many places it is suggested that the return line should be oversized compared to pressure line (low pressure drop on the return). So leaning to either steel or aluminum ones now.