Re: do you think this is an double die?
That appears to be a late die stage Jefferson nickel with mechanical doubling. Only thing that is wierd about it is the Mint mark, which should look different if it was mechanical doubling. Almost looks repunched, but the mint has used a single press procedure for years now, to eliminate the true double die from occuring, supposedly. as late as 1995 the mint admitted that it was still possible for one to occur, based on experts pressing the issue with them. Not sure how that one turned out though.
An interesting piece, though. You may want to have it looked at further. I'm no expert by any means.