Looks to me like something someone made, but maybe it is real. They are selling it like it is real.
http://lasvegas.craigslist.org/atq/1779892962.html

wow, that is different,thanks for sharing

The machine has been removed and a desk top put on. Who knew something invented by Frankenstein could sell for $700!

Hehehe. :P That's just what it is! I want to know who would buy such a thing!

It looks to me ( besides being a great idea ) that they used the top of an old dresser and substituted the plywood for a broken mirror. More storage and suppose to be quaint but I think someone did put it together. Mercy, the two pieces appear in the same era so why not.

It says "converted" into desk.

My thoughts exactly. I think it's awkward and ugly. Good luck on getting $700 for it! Who'd want to sit at that "desk" with the treadle still in place? Although, it might make a nice footrest. LOL

Years ago my great aunts had an antique piano made into a dresser for a bedroom. Go figure!!

It just doesn't look right to me. I sure wouldn't pay $700 for it.

Interesting! I might give them $50 for it...much like someone would pay for other sewing related things to decorate their rooms...certainly not worth $700