Ive just seen that someone spotted the vent......strange things happen trying to work on this site...
I went back to my first scan done at a very high photo rate but you can also see what may be a vent in the dorsal surface of the fuse above the wing trailing edge....it would also appear to have been two tone, there is also a diamond pattern on the sides of the fuselage mainly below the cabin but reaching back over the wing.
Heres a link to my Seagull research elswhere...if anyones interested In contributing will set up a thread here as well.
I deleted the previous small thumbnail and here is a bigger version of it. notice there is no rego applied in this photo so it must have been taken prior to the hangar shot.
Useful picture Kiwi,must get around to doing some sort of model of this one day.
With a modern small turbojet it would have been successful,I think they realised that there would be cooling problems with the Gipsy engine,not a motor that likes being cowled up and certainly not suited to pusher work.
A machine years ahead of its time and one that the replica builders could have a field day with.