I can get some better pics for you. I have it off of the loader now(had to put the bucket on to clean the wife's horse shed), so pics will be easy.
Material is what I had on hand. 2" square tubing, 1/8" wall. Gussets are 1/4" x 2" material, as well as hinge plates. I had some 1" ID x 1 3/4" OD tubing for the hinge pin pivots. The cross braces are 1/4" x 2" angle iron. There are two pieces of 1"x1" solid bar stock that go into the open ends of the loader arm that support the load. There are two pieces of 1.5"x1.5" square tubing on each side of the hinge area that are welded together because my hinge pin ends of the loader are 3" wide.
If I was buying material, I would upsize the 2" tubing for durability, but it has been holding up now. Originally, the tips JUST came together when closed. After using it for a while, they would close to within 4".
Yeah, I bent them. So, after gusseting the upper and lower arms, I added the plates to the end of the upper tubes to close most of the gap. Not that a 4" gap is bad, because you won't pick up anything that small. It's just dissapointing, as I had worked all the angles so that it just came together like a set of pinchers. Oh, well.
One other little project that I have thought of building for it is a tree shear. We have tons of wild red cedars in the pastures around here and they grow like weeds. If left unchecked, they can take over a pasture in a hurry. Because this loader articulates like a payloader, you can have one wheel 10" out of level with the other three, so rough ground isn't a problem. Much more comfortable than bouncing around in a skid steer. I have driven over 8" diameter logs while carrying wood out of the woodlot last weekend with no problems if you hit them at an angle. It crawls right over them.