We are actually not using this bellypan. It was designed more for the aesthetic of the rendering and would actually be useless because it does not prevent torsion in the frame much at all (because of the typography in the center).
Instead, we are using a waterjet 1/16" ABS bellypan with a few large pockets rather than the conventional diamond pattern.
As to the electronics, 1515's electronics for the past 3 years have utilized c-channel slides and either a reinforced corroplast or polycarbonate. We use WAGO X-comm modular terminal blocks to allow us to easily remove all the electronics in a matter of seconds. Is this level of modularity necessary, or perhaps even desired? No. However, it is a technique that has worked for our team in the past and we do intend to continue modularity in electronics in the future. It is something that our programmers and electrical students both very much appreciate as it allows them to work independently and free of debris.
The bearing blocks are very similar to the 973/1323 ones as Michael said, but with a different bolt pattern.
Please note that while this is a "standard" wcd frame, a much more recent iteration (except for the abs bellypan) is found
here.
EDIT: Also, the WCP gearboxes are anodized black and colors in both this rendering and that of our latest revision are simply for the sake of the rendering. (I actually helped with the WCP renderings).