Sandy,
Gaining freedom was buying a personal trade mark from the Company of Cutlers. Basically he had finished his apprenticeship and was striking out on his own. Some simply decided not to do that and just carry on working as an employee. It looks like Jonathon did that because the record does not indicate that he became a freeman.
The cost will be easy to find by Google.
My comment about the 1841 census was that there is no indication of relationship in that census. If he was born out of county he may have been a nephew for instance. That may explain why his baptism has not turned up. The best way to check would be to find him in other censuses, which will give his place of birth.
Dave