We've had quite a few volunteers encounter this issue and are working to change the functionality to allow community managers to update completed items. Read details in this discussion:
In the meantime, you can let us know of changes you feel need to be made by posting here or sending us an email.
I edited page 1 but when I tried to do page 2 it told me someone else was transcribing and wouldn't let me do anything. I thought if I edited it would free it up for you again. If you want you can check page 1. I found one typo but overall it was a great job!
I went back and was able to get into page 2. It is submitted for review. I hope you don't mind but I did make some edits However, it is a long article and I may have missed something.