[urq] MC1 oil cooler fitting

[Graham Allan]

Need to install an aftermarker oil cooler in an Urq, after transplanting
an MC1.

Does anyone know what the fitting is on the MC1 oil filter housing for
the oil cooler lines? I know (or think) the thread is 18mm x1.5, but
can't tell what kind of seat it needs. I need to adapt it to an AN
fitting, and when I look for adaptors I see concave or convex seats
listed - well, all the ones I see are concave, actually; however the
original hose fitting doesn't look particularly concave - just seems to
seal with a copper washer.

Does anyone know exactly what I need here, or have a good source?

Thanks!

Graham