Airy R. Bean wrote:

Can anyone direct me to a published design (URL?) for
manufacturing your own mechanical bug key?

Don't know about your skills with building mechanical stuff. Many
designs need to be able to work with brass & C.

This project is easily produced with paper clips
http://home.online.no/~verner/Clippers.pdf and works well if you're not
sending too fast.

Searching for "homebrew paddles" on Mr Google returns many links, and
some of them have a detailed description of building a more sophisticate
paddle set.

73,
Paolo