Good luck finding some, I've got a pair of 9"chromies with 235/50/13 BF Goodrich tyres still legal tread (But hard) and I know short of drag slicks I won't be able to replace them

Also got a set of 7"chromies but they aren't hard to find tyres for I'm running 205/60/13's on them.
Try Ben at Antique tyres, let us know if you stumble across a supplier of wide 13"rubber
Mick
