I have been looking for T-top info and came across this site....
Hurst T-tops
I have a '76 Monte with American Hatch T-tops ans was hoping to find seals. Mine are OK but I wanted some spares, looks like I'm SOL. However I have discovered for anyone with a '73-'77 A or G body that the Hurst and American Hatch tops use many of the same parts and with the exception of the inner retaining tab positions will swap.