I was given the following information about the Fullmer name and similiar spellings - I hope this helps a little:
A brief note about the Fullmer surname: Many books and articles attribute the variations in surnames to errors in the immigration process. Specifically, they would contend that Folmer, Fulmer, Fullmer, Fulmar (and others) are actually the same origin. Though this is probably valid with many names, it is not true of the Fullmer name and could be very misleading as you conduct your research. The double "L" is no accident. It comes from a German derivative "voll" meaning "person in authority". The names Volmer, Vulmer and Volmar had always been original Nordic, Dutch, and Scandinavian family names with a common origin. Vollmer (which became Fullmer), on the other hand, is not in the same category. It was more a label than a name. It was assigned to persons from foreign kingdoms (like Normandy and Saxony) who were placed in charge of conquered lands by their lord or regent. The label is similar to Officer-in-Charge or Ambassador-at-Large that we now use in our modern lexicon.