I was wrong about ADO 18...I cannot remember the exact number; But I don't think I was wrong about the make that I'm convinced is Austin Healey and not MG.
On the base project, Abington designers (particularly Dick Burzi) studied the A.H. and MG versions, perhaps with the overview of Michelotti.
The pictures I add are from MG model (named ADO35) and of the roadster Austin Healey (identified both as ADO34AH and ADO36). As you can see, the quiz coupè is much more similar to the roadster than to MG.
I logically may be wrong, but this is my opinion about this car.