I am no saw expert but my best guess due to blade being at 90’ and it having what appears to be two handles is some kind of planking saw ?

But you make your own mind up it has age my guess at least 100yrs old

Frame measures 85cm wide and 67cm tall

It has had historical woodworm which I have treated to be on the save side please see photos for old worm holes

Probably more for decorative purposes than useful saw

Blade and other metal work rusty but will clean up