First one has TEETH! Looks like sharks teeth in the front.
For sale a at a junk shop.
Skinniest crankcase
It looks like independent suspension at first look but a closer look and it's just a different way of mounting the wheels. The chain & lever in back looks like a clutch or brake control.
Sears number 123.8124 from Yard-Man Inc of Jackson Michigan.
I talked to the owner of this one. He is willing to see it go to a museum. Says it works fine. His complaint was it throws the discharge out the front so you have to keep cutting the
same cuttings. Just like a golf course greens mower. 18" wide cut. That means I couldn't keep up on my big yard as the grass would grow faster than I could cut it.