Perhaps you could try a shim inserted into the clamps with the blade as a temporary test.
A tool and die maker could make a set of these very quickly and would know what type of
metal has to be used so it has some spring to it. Metal too hard would just snap after it has
been tightened a couple of times.
I also own a set of clamps that I have never seen anywhere else before which came with a
cheap, no-name scroll saw. I'll try to describe them as best I can.
Picture a round piece of a bolt about 3/8" in diameter and 1" long with the hex bolt end cut off.
Then a hole is drilled through the center of that shaft through the diameter. (Through the side of the bolt)
Now a hole is drilled through the center of the shaft from one end to the other.
This hole is tapped at each end to receive a set screw on each end. The set screw on one end
should be long enough to reach the center of the bolt and you can see it through the hole that was drilled through the diameter. The second set screw, when inserted in the opposite end will screw in and tighten against the first set screw. When you loosen it (mine are allen head), a gap is created into which you insert the blade and then tighten the set screw to pinch the blade between the two set screws.
Since your saw wuold hold pinned end blades, these clamps will rest exactly where the pins on a pinned end blade would set and are automatically centered because they are cylindrical.
A set of those could be made by a reasonably accomplished machinist. The set screws have to be reasonably flat on the ends to make a flat surface to pinch the blade in to tighten.
A newby called wildhorse also answered someone elses post with this link
http://www.pozsgaidesigns.com/page0007.htmGood luck and God Bless! Spirithorse