Guys would also have a tractor repainted just to get it refreshed, and sometimes the newer 2 tone paint would be what they wanted. Lots of time this would be with a major mechnical repair like engine overhaul.
I have owned a JD R that was painted up and decaled as a 820. Have seen a few of the Cases like what you are talking about. As mentioned 70 series painted up as post buyout 94's. Lots of IH 400's with the two tone 450 paint and even emblems. Ford is another one it is very common on. 9n/2n's with two tone 8n paint and it goes on.