I, too, have great memories of my grandpa and his tractor (on his farm in Southern Minnesota -- near Lake Crystal). I finally completed a full circle when at the age of 55 I purchased a tractor like the one he had and then proceeded to restore it. I truly wish I had been able to share that adventure with him or someone else in my family.
So, here's a thought: Maybe you could focus on finding the right tractor to restore or upgrade with the plan of sharing that process with your daughters when they are a bit older. They could help you work on the tractor and then inherit it and pass it on to their children someday.
This is just a thought and one that I'd have enjoyed for my own life in a perfect world scenario. I plan on doing this same thing with my new grand daughter, if she is so inclined. I hope she enjoys visiting grandpa on his farm and becomes involved in the appreciation of old farm tractors, too.