Thank you
Kansas Kid, if you cross:-
Saxony = M+/M+,
li/li, e+/e+,
Bl/Bl, D+/
D+, Bu+/
Bu+, C+/C+, s+/s+, B+/B+, W+/W+, r+/r+, y+/y+
with
Wild-type (as in Mallard) = M+/M+, Li+/Li+, e+/e+, bl+/bl+, D+/
D+, Bu+/
Bu+, C+/C+, s+/s+, B+/B+, W+/W+, r+/r+, y+/y+
then you should get = M+/M+, Li+
/li, e+/e+,
Bl/bl+, D+/
D+, Bu+/
Bu+, C+/C+, s+/s+, B+/B+, W+/W+, r+/r+, y+/y+ as you have said, ie, similar to Blue fawn.
Progeny will be heterozygous (or impure) @ two loci, ie, Li+
/li &
Bl/bl+, while all other loci would remain homozygous (pure) for wild-type as you have shown
Yes, Both Li+ & Bl are dominant (incompletely so for Bl) over each of their respective alleles li & bl+ as I understand. The dark phase allele (Li+) should darken plumage generally (think wild Mallards vs Rouen Claire colouration). Those birds that inherit one dose of blue (Bl/bl+) should look similar generally to Blue Fawn Mallards, while those with two doses of blue (Bl/Bl) should look similar generally to Apricot Mallards ( I think you may call these Pastels?). Two doses of blue should lighten & even plumage, eg, lacing/chevrons removed in female. Try googling Blue Fawn & Apricot Mallards, or following examples may be helpful:-
Pastels
http://www.sherborneducks.co.uk/nscusadef_4.htm
Blue Fawns
http://www.sherborneducks.co.uk/USAColours-BlueFawn.htm
Cheers