C2 thread cutting ratios

I have a copy of Seig C2 Mini Lathe.

I started to set up for the thread cutting of a 1.5 pitch, following the recommended set up A 30 t B 40 t C 50 t d 40 t, the trouble is that the D setting doesn't connect with the rest of the drive train. If that is incorrect, I wonder what else is wrong. Could someone who has one, give me the correct gearing, for the metric and TPI, please.

Thanks in advance,

Kryn