Tell him something he DOESN'T already know.

Heh, thanks Michael. What I don't know and would like
to know is if my thinking with regards to ampere turns is
correct. Because I CAN wind a new solenoid coil with
a 1/2 pound spool of wire for about $20.

Do you have good reason to believe that AWG 30 is the proper gauge, and that
your calculations are correct? If so, then buy the wire and do it. If it
doesn't work, you're out only $20 and the time it took to wind the coil.

I don't know enough about solenoids to properly judge your calculations. But
I don't see anything obviously wrong.