Here are model numbers and codes of some of the first Nokia GSM phones:
Nokia 1011 | NHE-2XN
Nokia 2010 | NHE-3DN
Nokia 2110 | NHE-1NA, NHE-1NB, NHE-1XN
Nokia 2110i | NHE-4BX, NHE-4NX
Nokia 3110 | NHE-8, NHE-8BX
Nokia 6110 | NSE-3NX
Nokia 8110 | NHE-6BX, NHK-3DF, NHK-3XB, NHK-3XP