Got this gearbox trying to figure out what it fits

It looks tiny. Does it have FNR, different speeds, or just in/out of gear?
Walk behind mower maybe?
Has 2 speeds forward no reverse. The gear on the end of the sprocket works like a starter bendix. The lever on the end with the stamped number appears to lock the transmission from turning. The only way it appears to mount is with 4 3/8 studs the larger sprocket is approximately 9 inches and diameter the inner one being about 4 1/2 inches in diameter. Atleast 530 chain size and the overall width is 11 1/2 inches and the case itself is approx 7l x 7w x 5h thinking some sort of vintage motorcycle or scooter. When in gear the large sprocket and small sprocket move at the same speed the other gear is almost 2 rotations large gear to 1 rotation of the smaller gear.
Just an observation...and maybe you already thought about it, but that small pipe near the studs is probably a vent to atmosphere. It would be on the TOP of the case, not the bottom where the oil is. would appear the gearbox mounted under some kind of frame.
Do you have any guesses about those springs wired to it?