Hi Michael, and thank you again

Attached is the latest (work in progress) version, which still forms the two log spirals, with Blend by closest endpoints.
So I still do not have it right :-)

Blending code starts at line 111.

- Brian

 

(I previously had the central line connection working. And still have to do circular revolve, and match up tangents, so right now
only a pair of log spirals and (sometimes misplaced) blend occurs.)