The 4/44 was fitted with a 550-15 crossply, with the option of a 590-15. A suitable radial replacement for this is a 165SR15.
The 15/50 of 1956 had a standard 560-15 crossply, which can also be replaced with a 165R15 radial.
Precursor to the MG Magnette ZA, the 4/44 was more luxurious than nippy, but was a dynamic and fun small saloon despite that. The upgraded 15/50 was given a larger engine with more power to suit its looks.