One consumer credit licence will cover all branches of a company, as it is the company which is a legal entity. However a group which trades as a separate limited company at each outlet will require a licence for each limited company.
Consumer credit licences are issued by the OFT, not councils, and current licence details can be found on the Public Register
Public Register
A secondhand dealer's licence, issued by the local council, is required in most, but not all areas of Scotland. This is nothing to do with credit and is issued under the Civic Government (Scotland) Act.
On the final point, the legal owner under HP is the finance company, but if arranged by an unlicensed dealer, the agreement is not enforceable unless the OFT issue a validation order, so repossession by the finance company would amount to unlawful enforcement.