E-mail is a low-stress way to apologize... Your Dad probably forgot about it too, but nice that you apologized anyway.
While on the topic of tractors, I saw the strangest thing yesterday. On the way back from my daughter's house, I passed a field to see a guy driving a tractor, not as big as that Farmall, but bigger than a Ford 8N, with a tow strap out the back, pulling an old horse-drawn style single bottom plow being guided by an old guy on foot! I have never seen a tractor used as a horse before. I guess they didn't have a plow for the tractor - or - nor horse available!