83 KZ750-F1 LTD gas tank

Can anyone tell me if there are any other gas tanks that will fit on a 1983 kz750-f1 LTD? I have looked up part numbers and have read in other places that the tanks are specific to these bikes... I'm having a rough time finding the right tank.
Any help is appreciated. Thanks!

Probably the 750-4 Spectre --- 82-83 KZ750-N1/N2 . The Spectres are shaft drive.
I think they have the same frame & rear fuel tank bracket, so I'd guess the tanks will swap.
You can compare the stuff at Partzilla.