I looked a little closer at the map from The Problem of Lithuanian Boundaries, and noticed some very small dotted lines which appear to indicate areas lost to Latvia. There is no mention of it in the map legend, but I see the same dots around Palanga, which is the area mentioned as gained by Lithuania in the treaty. Some of towns within this northern area appear to be Snikere, Adzuni, Kamarde, Brunava, Akniste. There are likely more towns affected, some being right on the border. If you would like me to scan this map, send me your email. You can find mine by clicking on my name in this message.
You may want to look at the Ellis Island web site for arrivals that have the same last name, and try to determine their point of origin. It's a long-shot, but worth exploring I think.