I'm not quite sure where you get the 7T per week for FY17....

I'm not quite sure where you get the 7T per week for FY17. Because they've actually raised their capacity over time, not in one hit. Perhaps  exited FY 17 with the ability to produce that much. 

on the revenue side, they might produce that much, but some of that powder also goes into the oils, which have a lower selling price.

On price, they've actually reduced it since FY17, so I don't know what they were charging then.

and doubling of production to 15T didn't just happen at the start of financial year. I'm not sure when it occurred, but the numbers are never that clean.

As for PAT margin, the first X tonnes have to pay for fixed operating costs. It's once they cover those that you can look at the variable model I mentioned above.