Your examples all look like symmetrical examples that are called "Classic Plummets" and are generally dated to the Middle Archaic, and in your neck of the woods, as you stated, the resource adaptation was known as the Maritime Archaic. The later plummets, which are made the same way, but often asymmetrical and just not made as carefully as to symmetrical form, are known by the somewhat pejorative term "Clumsy Plummet", and that less well made style dates from the Late-Transitional Archaic. I'm sure all your classic examples are associated with the Maritime Archaic level at your site.
For comparison purposes, here's a clumsy plummet from RI. Nowhere near as much shaping involved; it's just a groove around a pebble: