I have now decided on a scheme and painted the underside.
But you haven't done the underside of the starboard tailplane black too, I hear you say. No I haven't! The instructions would have you do so because they have seen this photograph of the aircraft in question (without my arrows).
The red arrow is pointing to the shadow of the engine nacelle on the wing. The orange arrow is pointing to the shadow of the fuselage and lower fin on the tailplane.
This is not the black/white scheme of the early war. It was a short lived scheme of late 1940 and early 1941. On 28 November 1940 an order was issued that
the port wing only be painted black, but implementation was delayed until 12 December. At the same time underside roundels returned, with yellow around the port roundel. On 8 April 1941 the order was given to revert to an all Sky underside, but implementation was again delayed until 22 April.