Each one of the byd modules had these two busbars, which I removed while removing the heatsinks, fans and such. So I have 8 of each type.
One is a flat wide bar of what appears to be stainless steel. I flattened out the bends to make one long flat piece and will use it to be the interconnect between the two 24v halves of the 48v bank. With all cells paralleled, this one bar will make all the interconnects. Might double up (use one on top of another)
The other one is 1/8" thick copper wrapped in black electrical tape. Removed the tape and buffed off the copper. Will use one as the positive and another as the negative busbar. Might double them for 1/4" thick busbars.
Tomorrow will drill the holes and bolt things up. Then it's on to paralleling the cells.