I believe there is an old 17-pounder sitting in Prospect Cemetery near where I live. It's obviously a little worse for wear and has been painted and repainted a few times, but it's easily accessible.
I'm not sure if it's a wartime model (forgive me, I'm not certain if there were post-war models - I'm an amateur at these sorts of things), but I could take pictures of specific parts in high resolution if it would be of service.