FOUND THESE ON CRAIGSLIST BUT DON'T KNOW WHAT MODELS THEY ARE
#2
Fireman 123
The one on the left is a mid-70's Lawn Boy Utility. D-series engine. Unsure of the model #'s of those.
The one on the right is a mid-80's F-series Possibly an 8243/8243AE if it has the electric start.
Both are good finds. I'd jump on them if the price is reasonable. I personally wouldn't give much more than $50 for the pair.
The model number [and serial number -- you'll need that too] on most older Lawn-Boys is located on a plate attached to the rear of the deck -- basically below the gas tank.
I've found most of the mowers in my collection on CraigsList.
Good luck with the projects -- let us know how they come out.