Go for it!! I did
The satisfaction of knowing you're doing it all by your self is priceless. Concentrate on keeping the business running and turning over. If you need any help with accounts, advertising etc. no matter how much you think you know or think you can do, ask someone or pay someone to do that for you. Concentrate purely on what you know and nothing more.
You need to be prepared to work every hour god sends, and work every one of them as hard as possible. You won't make any money for at least a couple of years. I still only draw as much as I need.
The words of wisdom from Jon on the tax man and VAT man are well worth taking on board.
The only thing I'd be sure of with taking on an established business, is that the existing customer base will keep coming to "you". Many small businesses do what they do because of who runs them, not because they offer this or that.