That Briggs looks like a 92508 from long, long ago. A decent engine if in good condition, but I can't understand why you'd buy it, since much better mowers seem to be available on nearby nature strips for nothing, from time to time. Someone half a dozen houses away from me abandoned a fairly modern Victa Powertorque a few months ago, all clean and nice-looking, kindly leaving the mower repairer's tag on it saying that the starter was broken. It looked to me as if the cup was slipping, which should have been a 5 minute fix. The little old lady concerned was taken for a ride by a dealer who wanted to sell her a new mower, it seems. I left it right there on the nature strip of course (2 strokes appeal to me about as much as fresh dog droppings) and it sat there for about 36 hours. There are frequent patrols by people picking up such treasures, usually they get them on the first morning they are out there.