RE: 4-40 left hand threaded nuts
Nuts are pretty easy to make.
[link=http://www1.mscdirect.com/CGI/NNSRIT?PMPXNO=1736886&PMT4NO=101419707]4-40 left hand tap[/link]
[link=http://www1.mscdirect.com/CGI/NNSRIT?PMPXNO=8250556&PMT4NO=101419744]3/16 Hex Stock[/link] Lifetime supply of nuts.
You will also need a #43 (.089 Dia) drill available at any hardware store.
If you do not have a lathe for cutting the stock, you can use a file, and hacksaw in a drill press.