Chris, 
My tractor serial number is 273915 C77E, which makes it, to me, a 1952 oliver 77 standard.

The block stamp above the left rear motor mount has 185220, and below it has m100.  Just double checking to be sure it is a waukesha engine. 

1. Is it a waukesha?
2. What would the paint color be for this one?
Thanks, Matt Bailey