Wolseley's large car looks a bit like a very large Minor with an upright grille, with a larger six-cylinder engine. Basically because it's a badge-engineered Morris Six. Wolseley's six-cylinder made more power though, and was more luxurious. Surprisingly modern suspension and construction.
Standard tyre fitment is a 600-15, or 640-15 crossply. A 185R15 would be a suitably sized radial replacement.