Left handed theremins?

Yes, it would be good to get a copy of those instructions.

The good news is that this helps verify that I am proceeding
in a correct fashion. Only difference is after the board flip I
was planning on drilling another set of holes though the bottom
of the wood case so I could adjust the coils without opening it.

You only have to drill the bottom holes. You flip the board upside down, not around.
I haven't seen the instruction manual since building the etherwave, or I'd scan them.