This particular H-box is off a Honda CX650ED:

Rotated 180 degrees:

There’s a couple of items of note stamped into it – first, SANKEI 2130:

…and elsewhere, HMMGO-A:

Some more brackets:


A couple of other bolt holes:


We’ll have an article showing the internals in the future – stay tuned.
Tip to tip (front to back) the CX650ED H-box measures a hair under 320mm.