My secret source is my town transfer center. It is amazing what people are throwing away. Good Luck, Rick
The transfer stations around here used to be a decent place to find parts for push mowers, but now that the metal recycling stations are making you provide a statement of ownership when you bring in metal, you might as well forget the small fee for parts policy that some transfer stations had. With all metal being dropped off at the stations being property of the metal recyclers I doubt the transfer station can even allow you to touch mower parts anymore.
In order to get to the "gold" before the metal "recyclers" get their hands on it you have to find it in people's yards, and that's only when it's already "On the curb". Lawn sales, estate cleanings, maybe even auctions have become the only way to get to the "farm fresh" vintage metal unless you find a stash in the middle of a person's private property.
Vermont is that far gone. If it's in the open it's probably "Junk", and if it's junk you can't let it show, and if anyone objects to the junk or the fence you get fined until it's all gone. Put up a building? Depending on the town I hope you've got the money for the permits and pubic relations effort to build on your own property. Sorry for the political rant guys. We used to be able to find the goodies fairly easily, but as more oppressive regulations take effect for the sake of the environment, while they place huge ugly windmills on our naturally beautiful hillsides, we're forced to ask to look into peoples barns and other buildings, or pay premium prices for junk.
We also have to contend with cars running around with big hand painted ads on them that say, WE REMOVE YOUR SCRAP METAL FOR FREE. CALL XXX-XXX-XXXX The newspaper ads have been around for 20 years or so now as well.
I think you can see why a person here might want to stay quiet about a place offering a dozen or more vintage lawn and garden tractors for sale. It's the Black Market you know. Knock twice, whistle Hail Britainnia, spin three times to the left, and say Tony the Greek sent me and you're in.