Darren, you know your situation more than anyone, if it must go, it must, but it would sure be great if you could keep it. The ties to your dad and your birth year are real neat. (besides, it is a great looking Cub!) I have no practical working use for a Cub at my house, I live in a neighborhood and push mow my yard. BUT there are other reasons... and I am sure this post could go on and on with supportive reasons to keep it
You can't hang on to everything, but some things are worth trying more than others, you have to make that call. We have all got rid of things we wish we had kept, not sure how you really make that call, just follow your heart and billfold and good luck in your decision.