Could the gray 804 actually be a dull aluminum? Aluminum would be correct for 1930. There was a set in 1930 had a 803, 804, 806, 807, 902 with a 258. It's number was... 233.
The yellow 806 is throwing me though. Early green body, but typically orange body by that time. Yellow isn't in that list. The 803 is likely peacock, which depending on the month it was painted, plus aging, could look like anything from blue to green. The same is true of a late 20's to 1930 902. Pictures would be good.
