My first post.... so please be nice!!
I recently fitted a dynastart to a RD1 as starting it by hand was becoming difficult in the depths of winter and I did not want to feed it cold start every day.
Starting it with the dynastart is much easier, as long as it turns in the right direction (school boy error on the first attempt and yes; different dynastart turn in different directions and you cannot reverse the polarity as a quick fix).
Unfortunately the RPM of the engine at normal working speeds did not provide a sufficient capability to charge the batteries through the dynastart so I piggybacked the original alternator just above it and powered it with a double pulley from dynastart.
I took this photo before I had finished tightening everything up, but i am sure you get the idea.
If you need any more information, let me know and I am sure I can dig something out.