Nick: The bracket on my Trico holder is made of .055-.058 stock… It is part of the 2 inch wide strap steel that forms the bottom and sides of the holder. It is riveted to the surround strap that is of .068 x 3/8 steel. There are no small bolts, the rivet are spaced 1 5/8" apart.
If you need to make a bracket it is 1/2" high and 7/16" wide. It is attached to the circumferential band at a distance of 3/32" above the plane of the band.
My original Trico frame has the separate bracket that you seek. The bracket is made of .115" steel stock, 2 1/4" wide. It is “L” 'shaped. 1 3/4" x 1". Four holes are drilled .212".
Best regards
martin