When I was working on my Dark Mild last year, Denny suggested London Ale III. It was the missing link.
Denny, I think that you are on the right track with one exception. Go with a single hop charge upfront with American hop, Chinnock would be a good choice and dry hop. Mashing at 160 dF will give nice body, low alchohol, and the dryhop will shine thrugh.
I'll be curious to see how the 160 mash affected things given the SG I just got. I've been thinking about an early hop charge, too. I love the flavor and aroma from the late additions and I wanted the smoother bittering from a late addition, but I've started detecting a bit of "soapiness" in all late hopped beers I've done. I don't know for sure that late hops are the culprit, but they are the consistent factor.
Also, at this point I'm trying to keep to all American ingredients, so I'm avoiding a British yeast.
No doubt you know all "American" ale yeasts are of British origin, of course.....
Best English milds I have made, were using Fuller's yeast. If you don't rouse it, it drops quick, leaving a fuller, maltier beer.
Wyeast and White Labs are both on the Left Coast, so I would consider their products to be American ingredients.