Yeah they are ball jointed/ press fit ones. Know that the GJ (1980?) definately has the right arms. Pretty much any of the older models with the quad headlights. The earlier Scorpions had the same arms as well I reckon. If you saw the "newer" models arms you'd know straight away that they look nothing like the AE71/86 ones....
Interesting...how much modding is needed for the mounts and hoses etc?
R