Milton, as far as I know was the aerial antenna mast normally painted. As this was just a mast to attach the actual wire antenna(s) to. Paint would not have had any effect on the effectiveness of the antenna. On some Italian fighter (Mc202 for instance) the mast was made of wood and often not or only partially painted.
You could be right that directional (round) antennas weren't painted, however the streamlined foot on which they were mounted were made of the same material as the fuselage. Therefore, at least in my humble opinion, it is only logical that they finished in a similar way as the fuselage. Which is painted on the painted aircraft and polished on the late war polished aircraft.
Although the (aluminium) antennas from the Lichtenstein radar antennas on the Messerschmitt Bf110 Gs were painted as well (there are quite some pictures showing this). However the Kodachrome colour pictures from the P-61 show the antennas weren't painted.
The only original maintenance manuals I have are from early war Dutch aircraft. In the paint directives it says that the aerial mast has to be be painted in the same way as all other metal parts of the aircraft.
So as said I think the aerial antenna mast was normally painted (on painted aircraft). On the colour pictures I have been able to find this was the case. For the directional antennas I think only the streamlined foot was finished in the same way as the fuselage.
Therefore my humble question is it still easily possible to apply textures on them or would that be a huge operation?
Cheers,
Huub
BTW Milton did I already tell you that I'm really enjoying this aircraft