Your drawings are correct.
You might want to see if you can pick up on Ebay a copy of "Key Systems Service Manual", Vol I (tel sets) and Vol II (KSU's).
I installed and repaired approximately 3.7 zillion of these over the 30 years of my career. If you have a question, email me. One place I worked had 12,000 key sets, and 300 equipment closets. Every cable was a home-run, and we used no bridging clips.
Mount 66M-50 blocks and terminate the 25-pair running cables for each station, two to a block. Then you need to bring out all the features (that's what we call the TRAL&LG leads) on a 66B-25 block. It needs to be mounted on standoffs if you can't find the rare mounting brackets. I have used 3/4-inch long pieces of 1/2 inch thinwall conduit, or plastic tubing, with the mounting screws running through them, so that their front faces are even with the 66M-50 blocks of the station cables.
Mount some mushrooms for the 3-pair cross-connection wires to run around, and cross-connect the features to the appropriate buttons. The first X-conn to any station's first PU key uses all 6 wires. Subsequent X-conns use 5 wires. All 6 leads are punched down at the feature block, and at the station block, the O/W lead is carefully wrapped ("whipped")around the other 5 leads to keep them neat and tidy.
If this were a real installation, you would need to create enough feature blocks, using multiple wires, so that you do not need to use bridging clips at the 66M-50 blocks. That makes trouble-shooting easier. For your application, bridging clips can be used, but remember that any two phones that do not share all features still need individual X-conns.
For the dial ICM X-conns, the convention is T&R (Bl/W pair) Lg&L (Gr/W pair) and the O/W pair is used for the buzzer pair.
