Thank you for the nice comments!
I have been busy and completely forgot about this thread.
The m+ is the wild type mallard pattern. One list of color genotypes I have has the uppercase M+, but I am sure they meant the same thing as m+.
On the claret of the Appleyard male, I am not sure. I have never crossed them back to Grey, so I am not sure to what extent the light phase affects the appearance as opposed to the restricted pattern.
On the question of the color Silver, it is confusing, isn't it? I wish we had some Call breeders that might be able to elaborate more on colors that are Call specific since a lot of these colors are most often in reference to Calls.
It is probably too vast a topic to cover in one thread. For example, in Australian Spotteds (a breed that I raise), one blue dilution results in the Blue-Headed and two blue-dilution results in the Silver Head. In Mallards and some other ducks, one blue dilution is Blue Fawn, two blue dilutions is Pastel. In the Snowy series, several colors are instead called "Silver" (and the US colors are sometimes referred to differently as well). It can get very confusing.
As far as the sex-linked buff dilution, I think it is pretty common. Any drake that carries two buff (or brown) dilution genes can be mated to grey or black females in a sex-linked mating. There are several breeds in which this type of mating can be done.
Anyway, I hope this helps. I do have a list of genotypes that is too long to post here. If you want me to email it, just PM me your email address. Dave Holderread's book, "Raising Ducks", is also a great reference.