Sunday and tyre pressures

Finally there is more warm, dry weather so any excuse to get the Daimler out.  This weekend it was a trip to the tip, a trip to the egg man, a trip to Tesco and to a local cafe, where I felt obliged to park next to the Merc.

I have a question - any thoughts?  What should the tyre pressures be on this Daimler?  I have a handbook but the figures in there relate to the original crossply tyres.