Milt:
You are looking for "Disc blades". Don't use the word "plow" or people will think you're looking for a furrow.
The term "Disc" refers to the entire farm implement (see pic). You want just the blades.
Farmers are busy people, so keep it short and to the point. I would target the Central San Joaquin Valley, a few hundred miles north of L.A.
There are tons of them around. Here in Fresno, there are thousands and thousands of them. You can try calling used tractor equipment dealers. They will charge more, but you will get them quicker. I can store them until there are enough for you to come pick them up in a truck.
I think you will find even more, and larger disc blades in Monterey county, near San Juan Bautista, Salinas, etc. They grow row crops there and use huge discs pulled with cab tractors and caterpillars. Growers such as Tanimura and Antle, Top Flavor Farms, etc would provide you with a lifetime supply. Same as growers near Tracy, Stockton, and Manteca. You can try calling PCAs (Pest Control Advisors) to find used discs also. I would probably say you'd pay $5 cash for each blade, and a $5 fee for the guy who finds them. You'll pay probably $10 shipping each, so it's worth coming to pick them up in person. They are VERY VERY HEAVY. The weight of the disc comes from the blades.
You might get lucky calling Domries in Fresno and Madera. They manufacture discs. Or Meyers Ward Tractor in Riverdale, CA. Or Kuckenbecker Tractor in Fresno and Madera.
Hope this helps.
