Interesting Carrier/CMP Pictures on eBay

[Bruce Parker (RIP)]

Interesting photo which shows a cold wireless operator working a Mk.II 19 set. At first I thought it was a Heavy Utility, but once "un-negatived" it looks like a 13 cab artillery tractor with the radio mounted on some sort of table (facing aft) between the front and rear seats. Never heard tell of this before.