I wouldn't worry about it too much,the cars cost you nearly 300 quid so far,so take it for the mot and then you will have a clearer picture of what condition it's in,aleast you will know where you stand with it and what needs doing to it to bring it back up to scratch

also imo you will be reasured sooner rather than later that you havnt or have bought a death trap?,I'd be more worried if I bought a car for that price with 12 months ticket.