Eric
The development of the Aero model over its three years in production throws up many changes due to cost.
The 1936 Aero during some of the year had these cover plates fitted. For 1937 1938 a plain steel plate was used, it was cheaper.
So was it correct for 1937? no, but will it fit? yes it should, but please check your dimensions on your valve chest.
Regards
Steve