dial *#0000#

>>> import sysinfo
>>> sysinfo.sw_version()
u'V 3.42.1 16-10-03 NHL-10 (c) NMP'
>>> firmware = _.split(' ')[3]
>>> firmware
u'NHL-10'
>>>

>>> mapping = {
  'RM-51': '3230',
  'RM-38': '3250',
  'NHM-10': '3600',
  'NHM-10X': '3620',
  'NHL-8': '3650',
  'NHL-8X': '3660',
  'RM-25': '6260',
  'RM-29': '6260b',
  'NHL-10': '6600',
  'NHL-12': '6620',
  'NHL-12X': '6620',
  'RM-1': '6630',
  'RH-67': '6670',
  'RH-68': '6670b',
  'RM-36': '6680',
  'RM-57': '6681',
  'RM-58': '6682',
  'RH-51': '7610',
  'RH-52': '7610b',
  'NHL-2NA': '7650',
  'RM-49': 'E60-1',
  'RM-89': 'E61-1',
  'RM-10': 'E70-1',
  'RM-24': 'E70-?',
  'NEM-4': 'N-Gage',
  'RH-29': 'N-Gage QD (asia/europe)',
  'RH-47': 'N-Gage QD (americas)',
  'RM-84': 'N70-1',
  'RM-99': 'N70-5',
  'RM-67': 'N71-1',
  'RM-112': 'N71-5',
  'RM-91': 'N80-3',
  'RM-92': 'N80-1',
  'RM-42': 'N90-1',
  'RM-43': 'N91-1',
  'RM-158': 'N91-5' }
>>> mapping[firmware]
'6600'
>>>