The pre-WWII Angulons have a less abrupt end to the "coverage", so that the corner unsharpness is less obvious. For contact printing purposes, I'm willing to say that my 210mm Angulon covers 30x40cm (12x16") at very small stops.
I forgot to mention that I recently tried a 150mm Busch ROJA Wide-Angle Aplanat on 24x30cm. It covers, at f:64. Optimum sharpness is less than that of a Protar, but the price and availability more than compensate for that. A 210mm WA Aplanat should easily cover 30x40cm.