Looks like a Snapper series 6 or a Comet 30 with a later model engine and an aftermarket fuel tank & bracket. 10 or 12HP conversions seem to be preferred when the original 8HP engine wears out or fails.
I have a series 6 that looks similar except mine has the "bicycle" handles for the steering and the original 8HP B&S engine.
When looking at the pictures, it appears that the metal ID plate has been removed. It's usually facing forward and riveted to the flat surface on the left side, just below the seat (As seated on the machine)