I went brain dead yesterday and couldn't remember the details. The Alphins I found were in England, back in the 1400's near Melton-Mowbray, an area near Leicester in England. I made the Dutch connection because during that period, the Earl of Leicester was commissioned to go over to Holland.
I've done international searches for Allphin, Alphin, Ollphin, Olphin and not found much of anything. I've also search the emmigrant records to America 1500's to 1800's and not found anything. That's why I'm pretty sure that the name is a misspelling.
If you check with one of those shopping mall geneology places, they will put Alphin in Scotland as a derivative of MacAlpin, but that's really a stretch....they pick up the Alp part, then assume the rest. The truth is, I've never found an Alphin in Ireland or Scotland.
There's an Alphinton, England in near Portsmouth. There's always the possibility that the name was shortened. More likely is that, in the days of limited literacy, the actual name could have been anything (even Oliphant). It's frustrating. I don't think we'll ever find out what the origin is.