You've got quite a treasure there, it was your Great-Grandfather's, and now yours. You very well in the future may change your mind and want to use it. Take good care of it. It looks like it's in good shape but razors can rust if the conditions are right. I'm sure you know that, just make sure you look in on it from time to time, to make sure it's OK. If you plan on laying it aside for an extended period you might want to think about getting some Renaissance Wax to keep the razor in good shape. Alternatively some type of light oil, just make sure the razor is dry.

You've got a great resource here in SRP, if you ever need any more information or help.