I'm also interested in this, if any one knows where to buy a PCB with the correct pin layout for the BTDR-1 it would be nice.
Anyway I'm no expert but, judging by these layouts here, you could use the same layout for the btdr2 and btdr1, it's just different wiring.
I've looked at madbean's projects, and in their belton project they say it's not compatible with BTDR1, but i'm not sure if that is because you can't mount it on-board or some other reason, because on the link I posted it's interchangeable.
Anyway I'm no expert but, judging by these layouts here, you could use the same layout for the btdr2 and btdr1, it's just different wiring.
I've looked at madbean's projects, and in their belton project they say it's not compatible with BTDR1, but i'm not sure if that is because you can't mount it on-board or some other reason, because on the link I posted it's interchangeable.