I have only seen a couple Original 4/4's. Most have been re-engined with a later Ford engine. My '63 had a 109E engine and a push pull transmission. 1348CC as I recall. The push pull transmission is easy to use and I found it worked quite well. I had sourced a Ford Crossflow/Transmission and Robert Couch converted it for the New Owner (New Owner now owns a 2005 Roadster). Not sure what engine You have but would guess it is a 105E out of a Ford Anglia.
You have a very rare 4/4 IMO. Hope You keep it Original and enjoy it.
Tell Your Brother in Law, to enter this Morgan into the "Amelia Island Concourse". I bet He wins an award.