I don't remember too much about Midtec, I know they made a few MK2's, I believe they were as well made as a Midas, perhaps even heavier.
The owners club are using that photo as an example of a late Midas MK2
http://midasownersclub.co.uk/history/They did develop the convertible Calico from a Midas that never made it to production.
This car it would seem it has the donor car registration, if it really does say 1979 it will be one of the first Midas to qualify for a free VED in 5 years time, assuming the tax system remains unaltered again. It really should say something like radically altered car in 1991 or something like that IMO.
I notice most historical Midas articles make no mention of Midtec at all. I'm fairly sure illness was the reason the company closed.