Vrakking tyres offers some new and used 9.00-16 tyre options. I suspect these are for the standard US rim, i.e. 15 3/4" rather than the wartime British size of 16" diameter, but I thought it was worthwile to post them in this thread:
Did I read Dunlop Trak Grip?!?
No connection and/or experience with the company.
HTH,
Hanno