As above I reckon its a good opportunity... Maybe a visit to the bank ?
One thing I would think about though is the guys son.
Like you said he's been working for his dad, knows the round, knows the custys and knows the prices. If you do decide to take it then see what his son will be doing.
If its well priced work you could offer to take it at 3 times, but pay a % up front... And then 3 monthly installments.