Thanks so much for all your help! This time CD has the correct answer.
The one nut was the "jam nut off of the bolt that your presser bar lift lever pivots on". I looked up images of the machine and sure enough there was a nut on the outside of the head. Thanks so much CD.
The other one was, as I thought, from behind the needle bar crank. I eventually got it in with the help of magnets.
Still can't figure out how to get the presser bar clamp off; oh well, I guess it isn't really necessary.
Thanks so much you guys.