Neppy, the Trim Lever was I believe the Height Adjustment Lever from one of the companies other products.
1985 at Edinburgh, I can only remember 2 Airtourers there at that time and neither owned by Jmac, a rego would be good.
Bulldog, I think you are refering to the "Swift". I spent many hours with HKM sitting in the mockup doing the cockpit layout and seating position. It was a tandem seater and also had the side stick.
I have many hours in Airtourers and Airtrainers and with HKM and a Black Douglas, all of which were "enjoyable".