Yes, since you took delivery for 9 weeks, it is reasonable to concentrate on the 11 weeks you didn't get your share. You could make a claim you didn't receive full value for the other 9 weeks, but just accepting it makes your claim for the unfulfilled 11 weeks even more reasonable.
Yes, you could claim for the 70 pounds of meat you did not get, because you bought your share with the clear expectation of getting that meat at the end of the season.
In small claims court, you should be able to get your filing fee and the cost of the service. This will be added on during the court session, if you win. Remember, nothing in court is a slam dunk. Make your case in a reasonable manner and be concise. I had one case in Spokane where I was supposed to have 5 minutes to present my case but the judge didn't even give me 3 minutes. She was a real tyrant but there was nothing I could do. My landlord got all the time he wanted to speak however. As I say, it can be a crap shoot. Be prepared, be precise, follow procedure.