They are so beautiful!
I saw the other day where Janome is making a treadle machine ... I may have to research it - - it sounds practical and fun!
as far as quilting ... you have the piecing downpat ... are you considering doing free motion quilting? (difficult if you can't keep the feed dogs from interfering) or are you considering just straightline quilting?
Without knowing your level of experience, it is pretty hard to know where to start helping ... or are you actually just wanting input about the treadle part?