Normal Sturmey Archer first 2/3 represent model underneath that you had month and year or just year.
so AW would be model then month and year. They had K KB KBC KS KSW and KT all from the 30s but dont know of anything K5? the origanal patent was 519 from 1902 you could try looking at the Sturmey Archer heritage site. I will have a look in our old sutherlands manual tomorrow see if it mentions anything.
