SOLD. Thanks Matt and TRF!
Mint 98% Girard Perregaux Rubber Strap. Actually the material is a silicone very hard as opposed to rubber.
This is standards size for Seahawk II 42mm and GP watches. 21mm at lugs, 19mm at deployment, 75mm X 120mm.
Approximately 20 wearings, no discernible wear. These never come up.
$260 shipped within Continental US via PayPal. International shipping actual carriage.
Many, many references.