I see it referred to as a 4 cylinder 1500. From my recollection [and the wagon I owned] they were powered by an Aussie blue flame six
Wosleys had a 1500 4 cylinder and replaced it later with the same Austin Blue flame 6 to become the Wosley 24/80.
Interstingly there were a couple of MGB's running around as test hacks during BMC /Leyland times here testing the Blue flame six and from all reports did very well. Never got past the test stage when the parent company fitted an English 6 and thus was born the MGC