Personally, I'd look at the length of time the company has been trading, how long the the customers have been with the company and what contractual agreements (if any) are in place to ensure short term stability.
One point that interested me, and on which I'd appreciate opinions, is the value of the stock and equipment in relation to the turnover. If stock, vehicles etc have a (depreciating) value which represents about 20% of turnover, it suggests that there's either been a spending spree somewhere along the line, or that business has fallen away leaving a stock excess. On the other hand, I could be completely wrong and there might be a valid reason as to why this figure is so high..
Callum