I believe a Nash "Metropolitan" is the correct knob. I tried to locate one and finally just gave up and put a regular cabinet pull on. Looks the part, not original but neither is the car. They are hard to find. Good luck, Matt.
He was asking about the latch althought the pull looks like something I've seen but can't remember where, like a Triumph Herald or something. Those early kit cars were an eclectic collection of parts weren't they LOL.