Here are a few more photos that might help you better understand the MY splitter drawing.

The first two show the mirror and/or PDBS holder, which is difficult to see in the drawing. The *03* and *08* photos made me realize that I did not record the serial numbers of the splitters that were installed in M265 - dough. Most of the threaded holes in 03 : 08 are for aligning and securing the internal mirror and collimator holders.