The car has given up one more secret! I was looking at the build data for the Wolseley Hornet that donated its fabric saloon body to this Minor chassis:
Body No.WF.527 (fabric, coach built cars are WM).
Car No.82420
Engine No.1260/5PU
Distributor No.789(Lucas).
Dynamo No.16943(Lucas).
Axle No.1352/5RA, (ratio 9/43).
Black with Cream top.
Red Rexine.
Black wheels.
Date of delivery 24 June 1930
Date record sheet 26 June 1930
The body is described as "black with cream top", but we all know the top half of the body to be painted mustard yellow - in fact yellow enough to make it difficult to describe it as 'cream', even accounting for some mellowing (or yellowing

) over the years. The sales blurb for this car also describes the fabric model as black and cream. And the mustard yellow superstructure doesn't really go with the red/brown interior trim - a most odd colour scheme.
I know that some manufacturers were in the habit of applying a coat of paint over their fabric bodies, and the lower, black areas of KR's fabric are also painted black. However, I always wondered about this back in the time before we identified the body as being of Wolseley origin, and assumed that one of the past owners had applied the paint. Indeed, it has quite obviously been brush-painted, and not to what I would think was a manufacturer's coachwork standard.
So perhaps the Hornet fabric bodies were fabric covered in two colours, and not painted at all? For this to be possible, the fabric had to be joined under the waistline beading, so last night I took a close look - particularly where the fabric wraps around the B post. Sure enough, there is a join. Further close inspection of small areas where the paint has peeled revealed a very much lighter fabric under several layers of paint.
So my conclusion is that this body was originally black and cream fabric, so when I finally come to re-fabric the car, I will return it to this original scheme at which time I might re-name it the Guinness Special!