Stretch,
There are 2 Pick-a-Part Auto salvage yards listed for Fort Worth Texas. Maybe one of those would have the size of used tire your after.
Pick-a-Part - 1720 Riverside Dr, Fort Worth - (817) 335-4699
Mr Salvage Pick-a-Part - 2366 South Riverside Drive, Fort Worth - (817) 413-6505
Marv