A.M. Ground Camera type S.4

Hi all,
I have a large format plate camera here for restoration. It is a full plate format (6.5″ by 8.5″ negative size) monorail studio camera made by the Houghton Butcher manufacturing company. I assume it dates to the 1930’s. The data plate reads:
Camera Ground S.4.
Ref 14A/685
A (crown) M

It carries the serial number 185. I assume it was used for the production of photographs for AM publications (e.g. aircraft profiles) or for squadron photo shoots. I’d be grateful if anyone could confirm this.

Restoration will involve repairing or replacing the leather bellows (linseed oil and saddle soap should get them supple again). The front and rear standards and rail are in good condition and only require cosmetic attention. A lens and shutter need to be fitted to the lens mount and a new ground screen made.

Robs