I've been sorting out some of my dad's tools and come across a 14inch 10tpi brass backed tenon saw. The back is stamped Refined Cast Iron Improved with the saw maker Thos. Turner Encore Sheffield. However the medallion on the handle Warranted Superior with a crown over a shield and a lion to the left and horse to the right and Dieu et mon droit in a swag below. This medallion I believe was used by Tyzak. The handle is quite worn with gouge marks where the screws have been prised out at sometime. The drillings in the saw plate are original. The handle has a well executed repair to the lamb's tongue section. Dad used to sharpen and set his saws himself and this saw handles and cuts beautifully.
Hi Kedge, BSSM has a mark identical to yours which is dated around 1880. From the shape of the brass back at the front (so to speak), the saw could even be a little later, around the turn of the century. It is also possible that whilst the handle is original (screw holes in the plate that match the handle), the saw screws and medallion are not. They look a fair bit newer to me than the saw is. It should probably have had brass split nuts and possibly a ground flat "Encore" or W/S medallion. I have an Encore medallion on a handsaw but it is too dark to photograph it tonight. I will put it on tomorrow. This style of W/S medallion design was used from about the 1860's onwards by an awful lot of firms, not just Tyzacks. It looks a very nice saw and I am glad that it is still in use. Fred Edit 15/10/2015 Here is an image of my Encore handsaw medallion.