Looks good. I did similar, but customised a 12N plug (I think it was just knock out the centre pin) because couldnt easily find a 12S in Perth. I used this wiring diagram. Electronics 2000 | Pin-outs | 12N / 12S Connectors
Seems to work very nicely with a small 7W foldup panel - I use for keeping my 2-batt setup topped up when the D4 doesnt get a run for a few weeks (has so far avoided all low-batt warnings which I used to get occasionally).

