The rod spring 37202 is the return spring and should have pressure on the housing when the clutch is engaged.  The sleeve spring is an anti rattle spring the holds the release bearing on the yoke.  The important thing is to have the 3 112 211 screws all set to the correct length.

The pump shaft is gear driven from the crankshaft at engine speed.  The shaft extends through the pump to drive the mag.

The OC 46 loader would be the best machine because of the lower first gear and weight.   There were 3 engines used in the OC 46, a 4 cyl gas and 3 cyl gas and diesel.  All are rated the same horse power wise.  But the 3 cyl engines are much heavier duty.  The diesels are the best as all are dry sleeved and the sleeves are very hard and last a long time.  There are 3 version of the 3 cyl gas and diesel engines.  The crankshaft was changed twice so there are 3 diesel blocks and cranks.  The first two version of the gas engine are not sleeved so there are two gas blocks.  The last gas version used the same sleeved block as the diesel, so is the best of the gas engines.  So since the newest of the OC 46 loaders are 55  years old  it is not easy to find one with an engine that is not wore out.  Parts are available for them but the diesel pistons are hard to find.  If you are looking to buy a 3 cyl machine post the engine serial number and I can tell you what it is.  I have a loader with a new 4 cylinder engine and a 3 cyl diesel that is rebuilt and both work well.

The FD started life in 1936 with a Hercules  DHX engine.  In 1938 the tractor was upgraded and the engine size increase to a DHXB engine.   In 1941 due to a shortage of Hercules engines the FDLC with a Cummins was made.  In 1945 it became the FDE with a Hercules DFXE engine. IT was made until 1952 and then the OC 18 came out.

Yes, on the 5 gear model the Gov is not timed.  The mag is driven by the water pump and that needs to be timed.

Cletrac sprockets are cast steel, they can be welded with any steel rod!  6011, 6013 7018 etc.

The Auto-Lite MZ-4098 was the first starter used on the HG, from SN 5GA000 to 25GA377. At SN 25GA378 they switched to a Delco 11029602.  I to would recommend Zimmerman's, they are very good to deal with.

Well Jack, that is a lot of work! But it should last a long if kept greased.

Yes. I would use grease there, as there are no seals to hold in oil.

The outside part of the stub shaft is cast iron. That does not take weld very well.  I would clean the stub shaft well with a wire brush. Then get some JB weld or similar epoxy and use that to glue the bushing to the shaft.

They are about 1/8" thick. which is not much. There are grease fitting in the support bracket, but most that I have come across have never seen grease.

For the EN the serial numbers should be 1B00 to 1B946. There is also a model EHG with serial numbers 1R00 to 8R52.  Both had Hercules OOC gas engines. Could your B be an R?

The sleeve is a press fit onto the sub shaft.  They usually wear through on the bottom and split. The support bracket will wear out of round as you say. They can be repaired by boring them out until round again then adding a sleeve to fit.

The gross torque for the IXK is 86 ft/lbs, net about 72ft/lbs. The later IXB was about 10% more.  This is at 1800 rpm.

Yes, leaving the bellhousing in place will work. I have done that.  If I could go back in time I think I would be kicking them in the but!!