So, off went an order to QRF, purveyors of fine scale model artillery.
Here are the finished things, nice chunky models with a definite feel of the Airfix kit about them!
I'm normally a bit nervous about assembling metal guns as they can be exceedingly fiddly. Some manufacturers can be relied upon to go together well (Peter Pig) but others are a bit variable. These were nice and easy however, the trails fitted well in their locating lugs the barrel just squeezed in between the trunnions.
There was very little flash, just a bit on the trails and a mould line on the barrel which came off easily enough. My Airfix 5.5." guns have gunmetal breech blocks, but I did a fair degree of looking at photos of real ones and painted seems to be far more common so I left them in the base colour. I particularly liked the detail on the tyres which drybrushed up very well.
I did try and source some bareheaded gunners in shirtsleeves, and while they are readily available in 20mm, it would have required a moderate amount of conversion in 15mm and in the end didn't bother. Serving a heavy gun in full battledress and fighting order does seem a bit odd, but hey ho. A couple of the supplied figures are in leather jerkins, which I thought was a nice touch. At the end of the day, they are figures in brown with green helmets, so from a distance will do as 'Russians' if need be.