Perhaps the sleeve is just a liner that's supposed to be tucked inside the box....
Is the end furthest from the box sewn shut or left open?
I bought it at a charity shop that gets donations from the leftovers of estate sales. Items often. Still have the estate sale sticker. They price to sell.
Anyhow, here's a pic of the side that looks much more Chinese. It arrived in a box of Chinese antiques too. Sewing machines were invented in the mid 1800s so being machine sewn doesn't mean not old anymore.
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