Mystery Artist(s) 44 – Help Identifying Tooth Tip

Julie writes:

“…

 spent time on Nantucket as a college student in 1976-77.  I purchased a couple of pieces of scrimshaw while there and and think maybe the scrimshander was Peter LaJoie but not sure. 
 Also, I inherited a piece of very primitive looking scrimshaw from an uncle that was an antique collector. He died about 20 years ago at the age of 97.  I have no idea where the piece originated but it does seem to be authentic whale tooth cut from the tip of a tooth. I wondered if it was someone’s early attempt at scrimshaw.  It is coincidentally signed with a PL also although it is in script.  I’m sending pics of the items and hope you can assist me in identifying them. Thank you for your time and consideration.”Scrimshaw Cabochon with initials "PL" of a lighthouse and shipLighthouse and Ship on walrus ivory, small cursive "L" to the rightWhale on tooth tipSide of tooth tip with cursive initials "PL"Back and bottom of tooth tip
Below are the pictures Julie provided for us.  Can anyone identify the artist(s), and regarding the tip, would this be whale or possibly walrus?  Add your comments below.