Snows gone, so I refilled my Farmall's gas tank and tried to start up.
Immediate problem - fuel running out of the carburetor and air intake hose.
Obviously the gaskets were shot. I pulled the carb off to discover it was rustier on the inside than the out. Thick layers of ferric oxide lay on every surface. It was blind luck that I hadn't cranked the motor over and dragged all that crapped into the cylinders.
Being a little put-off by the prospect of sanding the whole thing clean,I turned to electrolytic anti-oxidation.
Three tablespoons of washing soda in a gallon of water, a chunk of rusty band saw blade as the sacrificial anode.
Out came my handy little 6 amp battery charger.
Up came the little bubbles, streaming off the electrodes.
Worked like a charm. Three hours took off nearly all the rust, and just about every bit of grease and sludge was scrubbed away as well. The electrolyte is a nasty rust orange, now.
Two interesting things happened though, possibly due to the fact that I was using a heavily scented 'washing soda' form of sodium carbonate.
First, the sacrificial anode grew the expected chunks of rust. What I didn't expect were clusters of green-blue crystals. They grew to about 0.5 - 1 mm in diameter over several hours.
Copper contamination in the washing soda?
Second, the gas bubbling off the electrodes should have been pure H2 and O2. Harmless except to inveterate smokers.
I couldn't smell anything (Sinuses clogged) but breathing over the tank while watching it work gave me a faint but noticeable chest pain. Perhaps some chlorine mixed into the output?
I used a stainless steel strainer to hold all the carb's small parts. Half an hour cleaned them up nicely, and the carb lies re-assembled on my dinner table, the size and shape of a human heart.
Weird similarity, there.

Found the problem with the starting motor: the clamps that hold the rotor wires on was loose.
Symptoms were that of all the sectors on the commutator, only that one showed no circuit to all the others, only to its opposite sector.
Oddly, it was not the sector that showed the severe arc damage, it was the next sector in rotation.
One problem down, sixteen more to go!

Tore the Farmall's starter down. A rather simple machine:


It was not turning unless I tapped the case with a hammer.
There is a couple of spots where the commutator is really eaten away:


Brushes look brand new, and with only a little arcing damage. Now to turn down the commutator ....without a functional lathe.
This should be an interesting weekend project.