Hey Holmey:
Just looked in the file cabinet and found a busted Linhof - the springloaded end flaps are broken off and it doesn't have darkslides, but the pressure plates on both sides are fine.
Yours for the postage.
Charley
ps: Just a random thought: 1.20mm glass plates fit easily into these Linhofs. Would sandwitching your screen and film between two plates be a useful technique? I get my glass from Dead Link Removed in Worcester, MA. They carry glass down to 0.40mm. They'll cut it to any size you want, and the pieces won't be more than a couple thousandths of an inch off from what you specify. Nice folks, too.