Many years ago, CRG had reproductions of the 67-68 shifter nuts made. These are the nuts that are used to mount the manual trans shifter housing to the transmission crossmember - shown on page A4 of the M20 section of the Assembly Manual (#14 and 18 in 67, #13 and 17 in 68).
These have not be repro'd by anyone else and we want to make them available to restorers. The price is $20 including shipping.
Paypal to my email or email me for my address.