>Seat mounting: again the seat (as well as the tank) came from Omar's.
>It comes with rubber mounted "captured nuts".
Just in case it's helpful, some vendors call them "well nuts," and you can get them at Ace or other hardware stores, as well as online:
http://www.amazon.com/NEOPlex-Pack-Signicade-Plasticade-Frame/dp/B001N12FUS
They are a bit limited, strength-wise. I used one to hold the seat/tail unit on my flat track bike to the frame loop and it pulled free.
Beautiful work, pregrid. Thanks very much for posting so many photos. My tracker is a rat; yours makes me want to take it all apart and do it right.
John
Cazadero, CA