Mogul, let me say Welcome to Autopuzzles!
It's good to have new members with great knowledge and the first thing I learnt here is that you never stop discover new facts!
I checked my files and it's true, there' not a single line about the AH model in several books (Beaulieu, Georgano's, Burgess-Wise, and so on.)
So I had a look in Kupelian's book and there it is a picture of an AH Model, that was a Six (2004cc) rated 12hp, just like the following AN model.
The AB was a 3 litre, 20hp
![Wink ;)](https://www.autopuzzles.com/forum/Smileys/default/wink.gif)