Richard,
1) LHO's lunch sack may have been the sack described by Buell and his sister. Oswald was poor, staying at some else house. He would have grabbed anything available to reuse. As I have previously pointed out, the sack may have been one that orignally contained curtain rods, which Oswald reused for his lunch. When asked about the lunch sack, he may have responded to Buell with an answer as to its origins (explaining the unusual length) not its current contents.
Frazier's testimony is clear. He asked Oswald about his lunch. Oswald indicated to him that he was going to buy it that day. Oswald did not carry his lunch that morning. He certainly did not carry his lunch that morning in a two-foot plus long bag.
Mr. BALL - Did you notice whether or not Lee had a package that looked like a lunch package that morning?
Mr. FRAZIER - You know like I told you earlier, I say, he didn't take his lunch because I remember right
when I got in the car I asked him where was his lunch and he said he was going to buy his lunch that day.
Mr. BALL - He told you that that day, did he?
Mr. FRAZIER - Right. That is right. So, I assumed he was going to buy it, you know, from that catering service man like a lot of the boys do. They don't bring their lunch but they go out and buy their lunch there.