Now, now Bill. If you can do the Kettenkrad tracks, you can do these.
First, no caffiene.
Second, don't do it when you are tired.
Third, take a big deep breath, exhale, inhale, exhale............ feel better?
OK, try again.
I have recently used Aber's 35 025 set for the Wespe. I presume that the 3 part clamp that is offending you is the one that has pieces that look like:
part a) A piece of roofing guttering (in profile);
part b) A curved "plane" with pins to go in the U and a lip that clips over the first piece; and
part c) A U shape with two holes in each arm for the other pieces.
If so, I tried 2 methods with these:
1) I used a staple to hold the main piece part a in place on a piece of plastic card. I pushed the staple legs through holes made in the card and then bent the legs slightly to stop the staple coming loose and popping out. The staple runs the same direction the real tool would.
Then I pushed Blu-tack around the end of part c to "fix" it to the card. Then I used two sets of tweesers, one to hold part b, the second a set of crossed leg tweesers (the type that opens when squeezed) to spread the legs of part c slightly, so the pins on part b would go in the holes. Then used a little strip of tape to hold part c closed around b (a strip on each side helps stop c popping out). The tape should not be too tight though, or you will bend it getting the legs around part b.
Then I attached the lip on part b to part a, using a bit of tape or blob of Blu-tack to hold it, in case of "Tweeserpult" (you could glue it now I suppose, but I didn't want to risk gluing it at the wrong angle). Then I used the two sets of tweesers again, one to hold part c at the bottom of the U, the second a set of crossed leg tweesers to again spread the legs of part c slightly, so the pins on part a would go in the holes. It is a bit fiddly, but works.
When the parts are all in place, carefully remove the blu-tack from the lip of part b and glue the joins. When set remove the tape and the staple. Slide the assembly over the tool handle, and "Bob's your Aunty"
System 2 was to glue part a straight onto the kit, instead of using the staple on the card. After fitting b and c together, I slightly embedded the assembly in Blu-Tack to stop the parts wandering apart. Then I used the two sets of tweesers as above.
All things said, I found the first option easier to get around, as it was on a reasonably large but flat plane. Kit parts have a tendancy to get in the way when you maneuver the parts in system 2, and too much use of blu-tack means extra clean up.
Hope these ideas help.
PS. "Tweeserpult" is when a part jumps out of the tweesers. However, if the part is never found do we say it committed "Tweesercide"?