Looks like a Jaguar IRS...the front end looks like Mustang II with a rack and pinion steering rack.
The door hinges look homemade....not that there's anything wrong with that, it just looks like they just stick way out into the cabin, which would not be the way the manufacturer would have designed them.
The frame looks like square steel.....that might help someone come up with a source.
One other thing that seems to set various kits apart is whether the edges of the rear area of the cockpit and the wheel openings are rolled or not...if you can post some shots of those areas it might help some of the ID gurus! That NF975 will mean something to someone!
Cheers!
Dugly
