There are two ways to approach the parts problem.
The way I do it is to look for old mowers on my local CraigsList. I've currently got three Lawn-Boys just for parts... and I'm always looking for more if the price is right.
The second way is to look online. You have a D-series engine. Some major parts (pistons for example) are hard to find and OEM parts can be very expensive. However, almost anything can be had on eBay. There's a thread in the Lawn-Boy forum (near the top now) discussing availability and pricing of D-series pistons.
Here's the good news for you: Ohio (and the midwest in general) is a great place to hunt for old Lawn-Boys. You're close to the source. Not nearly as many of those fine machines made it down to Georgia back in the day. :laughing: