[TowerTalk] Mounting rotor on 25ag2 top section?

[Carrington, Walter]

I have a Rohn 25ag2 top section (used);  this is the tapered top section that has a single vertical tube at the top.  It appears that the way the rotor and mast were mounted was rotor on a plate inside the tower a couple feet down from the top,  and the mast running through the inside of the tower section's vertical tube.  Is this a reasonable way to do it?  Should there be a bushing inside the tube (there is none now)?  Won't friction be pretty high? Do I grease the mast?  Will it ice up badly? (I live on a very windy, cold, icy hill)?
    My rotor has an adaptor that allows me to mount it directly to the section's vertical top tube,  but it is not as strong as mounting it to a plate inside the tower section.  This will be a temporary installation for the winter,  30' or 40' high.  I'll have a couple of long VHF yagis on it.
73,  Walter,  K1CMF