Crystal 2 light chandelier marked PATD. SEPT. 12th 1876

This is a 2 light crystal chandelier that is marked: PATD. SEPT. 12th 1876.  It was originally gas but has been converted to electric.  At the underside of each end of the crossbar is a lions? Head.  Where each side cross bar contacts the lower round center piece there is what appears to be a bunch of grapes.  It appears to be of high quality with no chips cracks or blemishes.  

It measures 27 " across the cross bar and 27" high not including upper and lower metal pieces.  The lower round is 8" diameter.  There are a total of 12 crystal pieces.  The PATD information is inside the lower round part and is difficult to read through the cut glass.  

My 84 year old sister was told, whe she purchased the light from an antique dealer, that it was a Baccarat.  I can find no name on the light nor a pat. Number.

She would like to sell the light but has no idea of it's value.  Any information would be appreciated.

Thanks.