So Mark is is legal to make something out of this whale tooth? If it is beach find it is a fossil? I thought something like that about it as I had some experience with old (pickled) walrus teeth back in 70-th. They were nice for the rings.
Whale parts are governed by NOAA, and the US Fish and Wildlife service. So there are two sets of regs you need to be aware of.
The National Oceanic & Atmospheric Administration regs have to do with interstate commerce of the material. In short, you are not allowed to sell it, or anything made of it, fossil or otherwise across state lines. You may sell it in your state and the owner can carry it to another state but you are not allowed to offer it for sale to, or accept payment from, anyone from another state. Examples are on the internet or through the mail. Nor can you take it to a knife show in another state and sell it, or a knife made of it.
The USF&W service is concerned with it's origin, when was it killed and what species is it. The tooth is obviously older than a couple hundred years. The accepted term we use is "fossil ivory" though it is not actually fossilized. More correctly it is "ancient ivory". It is still ivory material and not changed to rock. There in lies the rub, it is legal to use what we call fossil ivory, but some Fish and Wildlife Officers try to interpret that law to mean the strict definition of the word "Fossil" Since it's still ivory, they do not want to allow you to use it. It is subject to individual interpretation. The vast majority of officers will tell you, you can use it. If you use it and come across one of the officers that interprets the law another way, it will be for the courts to figure out. I have seen officers confiscate things from people and have to return it to them with an apology. I have also seen where people were sited, and prosecution started only to see the case dropped the morning of the trial(none of these cases involved me). Most of us would rather not have all the hassle, and expense.
All said and done, I think you are within your rights to use it however you like within your state (I am not a lawyer). For several reasons not having to do with legality, I personally would leave it just like it is, not the least of which, it is very cool and more valuable just like it is. We don't see those things around very much. Like they say, "They aint makin' them anymore"
Congratulations again on a great find, enjoy them, whatever you do. Mark