I don't have either, however the last pair I ordered was a pair of St James. So if given the choice of your three and keep in mind I do like the Asquith, I would chose the St James first.
Edward Green tends to be my favorite shoemaker, for a number of reasons however I have a number of their models now and I am ready to get a few of G&Gs at this point. So the thing for me anyway is that in my mind when I think of getting a G&G shoe the St James is the first one that comes to mind. It not only seems to be the most Iconic of the G&G shoes it's also one of if not the best looking one. The Asquith is a good looking shoe, but it just doesn't appeal to me as much as the St James does. Now hopefully the Last will fit.
I then figured out that they are the Legendary St James ii in vintage cherry - prob my best buy ever