R Diesel Dreams

From 1949-1954 John Deere manufactured the R Diesel tractor. Probably, maybe, one of the most convivial design schemes ever put on a tractor frame. This old girl can run all day on a little bit of fuel. Something that could come in handy in any age.
I've heard that these old "johnny poppers" used to be known for their ability to be very flexible in the area of fuel quality. This makes me wonder if this old two cylinder would run on biodiesel without any ill effects? The bottom photo is a restored R. The top is a sweet unrestored model that I found at a "used tractor dealer" in Mandan.