Cool, but I don't know about that pentouse in the bottom right corner of your left sketch of the monogham, its a bit odd that a penthouse is at th bottom floor. the Monogham reminds me of the sicknes mono (might turn off buyers if this were to actually exist)
so change the name to the wiltshire of buckingham, i think thats the style of name you were going for. finally, on the jefferson, that triagular part in the first scetch is a bit akward, and doesn't fit with she style of building your going for (i think) sorry to be picking at all the bad parts,other than those its quite good! (and the drawings aren't bad for sixth grade either)