cast iron tractor seats

here are two cast iron tractor seats, or, maybe I should say implement seats because only the Champion seat came from a tractor. The other seat came from a mower seat from the late 1800's.
cast seats have become very collectable, so much so, that a book has been written to show the rarity of some of them.
Cast iron seats are rated from 1 to 10 1/2. One being common and one of several thousand of that style. 10 1/2 being the rarest where there is only 3 or 4 known to have survived.
In this case, the Champion seat (green & red paint), is a common seat and several thousand are known to exist.
The other seat came off of a Wilber Eureka Mower and is rated as a 10 1/2 and is quite rare and desirable to find.
So why is the Wilber Eureka Mower seat a 10 1/2 rated seat? It's because the Wilber Eureka mower was a very poorly designed mower, which means that few were sold, so, there were less of their seats on the market.
This quality evaluation came from a Chicago Farm Implements Expo occurring sometime in the late 1880's.
P.S. If you are interested in starting a C.I. seat collection, here is something that you should keep in mind. You can paint the front of the seat to make it look pretty, but never, ever paint the backside of the seat, and never purchase a seat that was painted on both front and back. Leaving the back unpainted and original will show if the seat has a crack or was silver soldered to repair a crack.