The only new 40" tire you can get are 9" I believe, so original 40" wheels are not to desireable any more.
I've never seen a rowcrop model in restored condition bring over about $3500.00 tops. Wheatland, Orchard or wide fronts seem to bring a few more dollars. I agree with the other posts. For a rowcrop N/F loose engine not running and bad tires, $500.00 tops.