I do not not it all or much about the 850's, but I love them! They had both 46 and 48 inch skins. The pump on the the left is an early pump as I understand it because it has the visi and nozzle on opposite sides. Serial will tell the tale. Wait till you get the 'square pump'. There are two. One square and one rectangle. I have a rectangle that was 48 inch and needed skins and they are only made in 46 so I cut the pipes to make it 46. (but kept the original skins). Some different visi's, some steel parts as opposed to cast etc. etc.
Larry
Last edited by st.rod; Wed Apr 03 2013 08:24 PM.