I completely understand. Possibly if like I have done, and gotten a little more into it than just the early days, you will have opportunity to try other block style planes. Then if like I did, you just revered Grandpas plane, as I have done with my Dads, you will build a nice box for it, to protect it from the shop demons.
But I completely understand wanting to handle the tool your Grandpa did, and I had the pleasure of knowing my Dad for over 40 years, and spent many an hour in the shop with him. Still miss him every day, and would do much to have a few more hours along side of him. I completely understand.