Reminds me of a different but somewhat similar situation faced in the US by the Gamble-Skogmo holdings [0] - 4300 stores - back in the 1970s. The complex lashup (dozens of store names) was decades old, the aging owner wanted out, the purchaser went bankrupt in two years. Some of the pieces survived (Red Owl to SuperValu), the rest fell apart. Maybe a co-op could work.
Especially as it seems in this case the customers are all local farmer who probably know each other. They would save the 30% profit the company apparently makes. However if the current owner really works 15 hours a day and sleeps in the office to keep the place running he might have to be replaced by two employees, and with the 500k debt the whole thing may not even be worth it as a co-op.
[0] https://en.wikipedia.org/wiki/Gamble-Skogmo