[AT] oliver 1850 hydraulic pump

[dfolske at nccray.net]

Does anyone know the manufacturer of the hydraulic pumps used 
in 1850 Olivers.

My tractor would have originally come with a gear type pump, then 
there was an update to a vane type pump and finally an update to a 
different gear type. According to the service bulletins at my local 
dealer I have the latest style pump. I can get a new pump through 
them but I was hoping I could get mine rebuilt if I can find out who 
manufactured it.