Euan
I would be staggered to learn that No 19s were not fitted. The 11 was a bit of a limited radio and certainly not a standard post 1942
I cant imagine carriers were not fitted with 19s after 1942 say mid to late 1942 .
I know the first batch of Stuarts were around 1941 were fitted 40/60 11s and 19s because of production delays but buy the end of 1942 they were solid 19s .
My impression was the 11s went on to serve as base sets etc and the 19 was the standard.
http://www.qsl.net/ve3bdb/pics8.html
i am not sure when 11 production ceased in australia but I had suposed early on and the 19 was the standard as soon as stocks allowed.