As I recall, the threads are M14x1.5 with an o-ring under the head. Adapters are available in aluminum to convert to -6AN from Russell, and I'm working on a G-code programme to turn them out in brass at school (I don't have anything against aluminum, but I prefer something a little more solid for sheer reliability. Weight isn't that much of an issue for us - four ounces vice two is negligible.)
You'll probably have a hard time getting ends in that metric thread, but you can get them in -6AN all day long (and the hoses are 3/8" ID anyhow, which corresponds.)
Check the Russell catalogue for the adapters - I'm sure they're 14m/m, and there's only one thread pitch listed (which agrees with whatever I measured yonks ago.)
For the forward ends, the fittings are a little strange. If I were going in your direction, I'd just get an external cooler with 3/8"NPT and adapters or just a -6AN fitting pair and go that route.
5-90