[Stig Jarlevik]

Ah yes Graham

Unfortunately you are stuck with the old '1970s' view of the Heinkel 111.
William Green said so even back in 1998 that the D-0 and D-1 model was produced in 1937. That was an invention made in Germany simply because no one knew what the D-model was and there simply was a need for 'something' to exist between the B, C and E models.
We usually put all the blame on Bill Green which is not entirely fair, since the invention was most certainly made in Germany.

According to Volker Koos, the only documented proof of anything called Heinkel 111 D was 30 P-1 aircraft with increased radio equipment to serve as 'leadership aircraft' (Führungsflugzeug). They were developed from the He 111 V14 but I believe they were little or not used in their intended capacity.

The article by Volker is very short and the He 111 D is given seven short lines so I have not very much more to say about it.
The WNr (beside those I already mentioned) were 2101-2120.

Perhaps, what is worse, neither Manfred Griehl nor the Classic book 'mafia' were interested in listen and learn anything, which means that the He 111 book by Classic for example is very unreliable!!

Cheers
Stig