Unfortunately I do not have many of the Letter Series Manuals yet. I have some stuff for the A which still has to be formatted and uploaded, but not an Owner's Manual or a Service Manual. I would gladly host them if I can get scanned copies.. and that includes any of the Letter Series tractors -- for now.
I would think (and this is just IMHO as I really know little about them aside from a neighbour has one which I am trying to buy and my buddy has his Super A here), that as far a lubrication goes, it would be a pretty good bet that much of it is the same. The primary differences between the A and Super A is the engine and the hydraulics. Super A has Touch Control and the A has the Pneumatic Lift All.
Othes will chime in I am sure