This looks very much like a Glasair SH2 TD. These were good quality "Amateur Aircraft Kits" made in Arlington, Washington and marketed in kit form for home builders. The SH2 tells us that it would be a 4-cylinder model as opposed to the larger 6-cylinder ones. The TD refers to the landing gear, this one being a "tail dragger". Is this a natural progression for car builders to move on to planes? Roger Trethewey is now building up a plane down at Goolwa airport.
As for your Mark 7, Dave, by having your email on this blog, a reader may recognise it and let us know.