The 540 replaced the 410 and the 550 replaced the 510. we had a 410 before we replaced it with the 550. the 410 had a 14ft platform and the 550 had a 20ft platform. we farmed dryland wheat and milo.
I had a 540 mf combine and all it is a 300 made bigger and uses a lot of the parts as the mf 300 it has a 318 4 cy perkins engine but it has weak drives like the 300 Dan