This lawn mower does not have the electric clutch on the engine shaft, (I wish it did) blades are engaged with a lever on the dash next to the steering wheel.
It is a Craftsman LT 2000,
Model #: 917. 275520
Serial #: 033005C005305
Engin #'s on Valve cover
Model #: 445577
Type: 0485 E 1
Code 050324 G
Briggs & Stratton
INTEL TWIN 23 OHV