Hello Paul

Check out True Turn Spinners They make a spinner for a AT-6 that looks like the spinner for the Staggerwing. True Ture will also have the OS 1.60 adapter that your looking for if thats all you need.

Here is a link for the 2-3/4" adapter.

After looking closer at the web page that spinner may be too small from your prop. You may have to go bigger in Dia. to fit your prop

http://tinyurl.com/ce86bln

Here is the replacement prop adapter that your looking for. only $8.95 for the O.S 1.60 engine.
http://www.truturn.com/cgi-bin/store...8a&ppinc=adapt

Regards, Jim