I ought to be able to ID it but I'm not sure. A mate saw this at a reclaimation yard in Somerset. It is a 3.7 inch ? Edit. Think it is. Vickers QF 3.7 inch AA Gun
Ha. Found my pic from last year, mate. Bit clearer side view. Amazing selection of doors there... They seem to have gone around Jaipur etc. (where my old man was born, under the Raj...) & bought up every old door they could find. Cracking spot, if only for a browse.
Alas, not listed for sale on the website. There are few in museum and fortified places. I am sure someone would like it.
He used to have a T34 there which he finally sold in 2019. Wells man finally sells tank which he has had since 1993