You'd be better off switching to a 14" rim so you could keep some matching star hubcaps. 14" tires aren't too hard to find in a size which will give your car a good ride and will keep the speedometer correct.
If you want to keep the 13" wheels, then go all the way and get some Michelins or Vredesteins from Coker tire. You could always have two wheel sets, one as a restoration set with 13" wheels and one as a driver or maybe winter set with 14" wheels.

Phil Forrest

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1972 220D "Trudy," named by a friend.

"The 220D sounds good... I suspect it is the only car that you need a calendar for, rather than a stopwatch, when doing acceleration tests."
Tom Abrahamsson