Good point about other tooling methods (laser cutting not the only one
available), but the question remains, how many people would actually be
interested in buying plates, at what cost levels? (At the time I was
making the other parts, soft tooling was cheaper for very short runs,
but the shop that did the punch/die was set up to make such tools at
very low cost and easily beat the soft tooling for modest runs. You
just need to decide how many of your parts you want, and go shopping.)

As for using varactors on receivers loops, if you use back-to-back
diodes and don't have to deal with seriously big signals, distortion
should be at worst a very minor problem. For a fairly high Q tuned
antenna, the signal voltage across the diodes for signals you're not
tuned to is pretty small. Of course, the reason it's so hard to find
small (receiving size) mechanical caps now is that their job has been
taken over...by varactors.

Cheers,
Tom