There were some tyres advertised on e bay by a dealer who bought a large batch from France, the tyres had reached their sell by date but are otherwise OK.
I use Dunlop ,Mitchelin or Heidenau tyres, although the first two are getting harder to obtain.
John Ellis of AOMCC 2T spares or Keith Harding are the people to ask re the white walls. Some tyres accept them OK and on others they are very difficult to fit.
There are some white wall tyres but they do not look right somehow, I thnk they are made by Corker.