I have my fuel tank off right now and have discovered that it is badly rusted at the outer edges where it sits in the saddle. There was some kind of fabric or rubber between the saddle and the tank, that must have absorbed enough moisture to do some pretty deep pitting. I think that there is supposed to be some type of padding between the tank and saddle, but does anyone know what it should be , so it does not cause more rust?                   Thanks Folks,  Grant.

Original was a manila hemp pad similar material used in the seat cushion can't remember the correct name.
Yeah, Not a good choice though!
Probably should cut the bottom out and weld a new piece in.
Another idea although not original; is put a smaller tank inside depending on how much running you'll be doing.

Grant: Being the tightwad that I am at times, I have used remnants of tarp webbing or slightly used 2" web straps to cushion, or thin rubber belting. Something is better than nothing, and unless you advertise it, nobody would know except you. Can you use marine grade JB weld to patch up your tank, or is it too far gone? JM

origanial it would have been asbestos sheet , i had a new bottom welded into the one did

JB Weld sells a fuel tank repair epoxy. I am going to try it tomorrow. The pin hole is less than 1/8 inch and I dont think the area around it is as bad. I will sandblast tomorrow and if the hole doesnt enlarge, I will try the JB. I suspect that asbestos was the water absorbing cloth that caused this problem. I may epoxy rubber to the area that contacts the saddle. Hopefully no water can get under the rubber. Grant.

Welding Fuel Tanks?
Metal is porous. Steel and Iron "rust" which is a very slow "oxidation" process. Oxidation is Burning if you will, same as cutting with an oxy-acetylene torch.
Some have sucessfully welded on fuel tanks, others have not met the SAFE results, either maimed or killed.
There exists many that say it is a "SAFE" operation "IF" - the key portion being the big "IF".

Personally, I do not believe there is a "SAFE" and assured method, I vote for a Cold process.
Many will disagree, that is expected, but I would not get caught welding, cutting or grinding on a fuel tank. Confined spaces are perfect for incidents to occur.

STAY SAFE
Cts

I think that the JB Weld Tank Repair kit worked. I am going to use it as is , while I work out many other things on the tractor. When I have the other issues worked out, I will have the bottom of the tank re-plated. The local farm repair shop says that it is no problem. They keep CO2 flowing into the tank when welding. I would not attempt to do it myself, but these guys have done it many times before.
Grant.