I've been running round in circles over the towed equivalent of the gun fitted to the Churchill Gun Carrier. The only thing that seems consistent is that 50 were produced then either;
half kept for Home Defence and the others to the Middle East.
mounted on 17pdr carriages
mounted on 25pdr carriages
all kept in the UK after manufacture in 1944
Has anybody any hard information about these semi-mythical beasts please or clues where to look at Kew when I visit in the New Year.