I'm needing to fit a Schneider APO-Componon 4/150mm HM (55mm thread)to Durst closed loop Pictocrom head. The regular LAPLAR lens boards clearly won't work because of the small space available for the upper lens element.
Having tried Jens Jenson, I'm now onto plan B and hoping someone will kindly be able to offer the dimensions of a lens board that will do the trick. I'm guessing I can have a regular laplar board extended(?)

If you don't want to cobble something together yourself I'd recommend bringing the board and the lens to a machine shop. A competent tool and dye maker could churn out an elegant solution to your problem for under a couple hundred bucks and in under an hour. This is exactly what Jensen would do however he'd charge you twice as much, take six months, and then try to take you to small claims court.

My Schneider 150/4 Apo-Componon has a small extension cone that fits between the lens barrel and the rear cell. If you don't have this part, you might try ordering it from Schneider. I think it comes standard with the lens.

There are three ways of mounting this lens. One is with the cone, which is a direct fit in an Omega D lens cone in place of the small metal disk that usually holds the lens on the lensboard or the big cone. Another is with the 55mm threads. You can also unscrew the rear element from the barrel and attach the lens to a lensboard with a 39mm hole, using the rear element to hold it in place. I believe the elements are also a direct fit for a Copal 1 shutter, so that's a fourth option.

Thanks frotog that was the next approach.
David thanks very much, good information. The 39mm thread on the rear element would fit many standard lapla lens boards. But there would only be 20mm space available for the rear element above the lens board. I suspect it would need more than that(?)
The extension cone sounds like it might be the answer.

I have a beseler lens board for the apo 150 hm. Perhaps it would be as simple as tapping a couple of holes in your durst lensboard and attaching the beseler with a thumb screws a la omega boards.

That's sounds fine, if the beseler board is a turret type. What do they look like?

The beseler product number is (or was...it seems to have been discontinued) #8088. It's essentially a 45mm deep cylinder attached to a beseler 4x4 board. It probably will be more of a hassle than it's worth. I didn't know the pictocrom was turret-style. If the pictocrom takes standard durst mounting rings then couldn't you simply get a 55mm filter reducing ring, a small section of pvc pipe and then epoxy this to a spare durst mounting ring?

thanks very much frotog.