From the look on the intake ports, it is supposed to have air ports which someone has removed and plugged up. My humble guess is that it is a Caille Model 30 Racer with the Johnson mag and rope plate of a Model 200 grafted on it.
I messaged the seller about two months ago when he had it advertised as a Johnson 200 and told him it was a Caille. He had it up for something like $150 and no one bid on it. Not the first person in the world that didn’t listen to me.