some of the split doors had vents like mine but yeah they never had the screw and thick latch. the early ones had just a screw like mine and the later ones had a metal tab latch IIRC. Here the later ones always loose their doors it seems. the ones with the screwed in door never loose them. I love how my M-400A2 has the match to hold the dor while i loosen the screw. makes it a lot easier. With my M-250A there's just a screw but the power door is warped and presses against the refractor door, holding it snugly in place even with no screw at all but of course i still use the screw. You need to press the door in place best you can and when you tighten the screw the screw pushes the door all the way in place since the power door was dropped when it was removed (fixture's okay though and so is the power door dispite being slightly warped).