I have an old John Deere Lindeman BO that could use a new seat. But I've more or less decided to adapt an old cast iron Deere Repro seat that I found on E-Bay. If the cast Deere seat is "real", it probably came from a much older horse drawn implement.
It doesn't quite match the original pressed steel seat, but I think it will be a cool "upgrade".
Anyway, looking at photos of the Lindeman, I don't think the seat had a lot of holes. So, perhaps similar to the seat with 5 holes. I'll see if I can locate my seat, or find some better "original" photos. I fear the variety of seats I'm seeing online mean a lot have been replaced.