The only Ford with a 3 7/8 bore size in a 1958 Hepolite catalogue is
1928/35 24H.P A,AA,B,BB, Pass.20 Seater,Sussex,Surrey,Thames, Six wheeler, ½-4 Ton
1938/48 24 HP New Four,FC, Sussex,Surrey,Thames, Six wheeler, Rigid Six, ¾-6Ton
This is as printed in the catalogue. Tried scanning the page but it didn’t work