< Can anyone help me identify thie crest on this seal? Could it be a family crest or just an official seal? >
The seal itself looks, to me, to be the personal arms of someone. I couldn't find those arms registered in Britain (in Burke's 'General Armory', the 'Supplement to Burkes GA’, Morrant's 'General Armory Two', or Robson's 'The British Herald') under that surname.
The crest shown on the seal is what I would describe as a 'demi-Lion' but I couldn't find one that matched the image with the surname of Lever. Unfortunately, the crest isn't sufficiently clear enough to show the finer details (is the Lion collared/gorged, is the Lion holding anything in its paws, etc.). On searching through 'Fairbairn's Crests' the crest of a demi-Lion is quite popular being used by more than 50+ different surnames.
The design of the shield itself (as opposed to the incorrectly used word 'crest') I would describe as 'Per Bend sinister [two unknown tinctures] a Lion rampant'. This design is also very common being used in several hundreds of different arms.
I think that your best bet would be for you to approach the 'Officer in Waiting' at the College of Arms in London
http://www.college-of-arms.gov.uk/Enquiries.htm. The College, being the Heraldic Authority for England, Wales and Northern Ireland, has far more extensive records than I have at my disposal If you do have any positive outcome with any dealings with the College of Arms, it would be appreciated if you could let us know the outcome.
Sorry I couldn't have been of more assistance.