R. Groves & Sons Hand Saw Sheffield Brass Blind Split Nut
Antique 19 1/2" inch split nut Crosscut Handsaw made by R. Groves and Sons
This saw has blind solid brass medallions largest is approximately 3/4 of an inch in diameter. 
Brass split nuts on back.
The saw blade is marked R. Groves & Sons, Sheffield, Caststeel, Warranted and Corporate "use" Symbol/Trident.
The saw has 7 PPI teeth and a number of broken teeth (see photos). 
The handle is in nice condition except for the lower horn on the handle appearing to have been worn off.
The blade looks to be straight except for a slight bend, see pictures. 
The blade and handle do slip about 1/16 of an inch.
Saw was found at an estate and has only been touched up with mineral oil and steel wool, given its age there are signs of use :) but not too bad for a 200 year old saw!
If you know saws, you know this on stands out, display as is or refurbish further, your call.
Don't like the price...make a reasonable offer.
The saw appears to be from the Mid-1800's as provided by another user (thank you), it is likely dated to 1840-1850, comparably other sites on the internet claim earlier. Either way...its a great piece for the collection.