This is darling!! I'm so glad you are doing this!!
I haven't read all the post so this may already be covered!
I wanted to say that one of the reasons we are quilters is that we are perfectionist!! Ain't it hard!:) :)
My DM Hand quilts & does hand embroidery. She does not piece!!! For years she bought panels (very large ones) & hand quilted 'em. Recently she buys white preprinted embroidery squares. Next she does all the hand work on 'em & she sews 'em together. Then sandwiches & quilts. They don't line up!! She doesn't even try. They are beautiful!! No one even notices, the seems are all white, & we're all focusing on the lovely embroidery!
Because this is all muslin, the kids did the signatures, & the pattern is brick I don't think anyone will notice if this doesn't line up. Keep up all the hard work!