If you want to restock the No. 1, do it. You can save the existing stock and change it back any time, if you want. Having a buffalo engraved on it won't hurt the value if it's properly done, will mean a lot to you, and will become a family treasure to your heirs. An 8mm Turkish Mauser has never had much value, but the action could be made into something wonderful. I would do both of those projects.
Now I have my grandfather's long barrel Model 94. It's a little over 100 years old. I will never modify that rifle due to its history in my family and its monetary value to my heirs if they should want to sell it. So sometimes you should make changes to make yourself happy and sometimes it isn't smart. The two examples you gave are two that I would do.