Good to see you working on a dragline again jim-I know nothing about the clamshells except most of the models I have seen do not work very well. The weight idea is probably good. I like your technique on cutting the aluminum. Seems to work good although me being a wood worker I cringe when I see that.
My dad used to take pride in how good of an edge he could put on a wood chisel (and his pocket knife) so I'm sure he would not like this but I say what ever works. Is there any way to put a release line on the clam bucket? I think you said it had to go all the way to the top of the boom before releasing. Is that right?