Symmar 5,6/150 in Copal Polaroid ?

I'm looking for a cheap shutter to mount the elements of an old 5,6/150 Symmar (the old convertible, not symmar S). I tried it in a Prontor Polaroid, but the rear elements protrude too far into the shutter and jams the apperture. It's a question of less than half a mm, but too far is too far. Does anyone know if this lens can be mounted in a Copal Polaroid MP4 #1 shutter ? I think this is the cheapest alternative that's easily obtainable on ebay, and, besides, I like the press shutter type. I'm aware that the apperture is mounted further back in the press type copal, compared to the ordinary Copal #1. But I don't know if there's a difference between the Copal and the Prontor.

I have a 150mm Convertible Symmar that is fitted in a Copal Polaroid press shutter. This set up works quite well.

However, after doing some quick research on MP-4 shutters, it is clear that my shutter is another model. It has both a B and a T setting, but no preview lever.

Thank you. I think I'll try it. From the drawings posted on S.K. Grimes's site, I have reason to belive it should work. But the clearing is very small, so I felt a bit uncertain.

Andreas