FRJ, That's just the point... you can't buy it because it's illegal to 'advertise,' and/or 'offer' it, 'For Sale.' It doesn't matter if you can actually prove that the whale oil predates the date/year of the enacted regulation or law.
I wouldn't make it a point of even be 'looking' or 'inquiring' (on the street) to get some. Honestly, I think the Fed's would be more lenient on you if you were trying to buy enough SA/AK47's and drugs to start your own cartel. Now, should someone THAT YOU KNOW, PERSONALLY, FOR A VERY LONG TIME, should have some and just give it to you, that's an entirely different matter.
It is out there. I had a old friend in OR, that passed some years back, that had quite a stash of it that he used for his 'personal' muzzle loading shooting and oiling his locks. What happened to it, is anybody's guess.
That said, if I am, in the least, in error, please don't hesitate to correct me.