10/30 and 11/40 models were fitted with a 760x90 beaded-edge tyre.
The 12/40 initially had the same beaded edge 760x90, but the later TD version of 1925 went to a crossply wheel and tyre instead, in a 29x4.95 (500-20) size. Check very carefully whether you need a crossply or beaded-edge tyre!
Alvis's first production car, the 10/30 was upgraded annually as engines and technology rapidly improved. Found with a range of body styles.