Starting Trouble-'74 WM

[MikeIIDC@domain.elided]

Okay, I am so damn close to having this '74 Wagonmaster on the road that
it is ridiculous!  And yet something ridiculous keeps coming up and
screwing it up!  I got a gas tank back on there, got enough gas in it to
turn it over and get gas up to the filter just before the carb and after
the fuel pump.  To do this I took the battery out of my '71 Scout and
used it, then, when it wouldn't turn over anymore (and not dragged down,
but just turned once with the key, I released, got out to check fuel
directly into the carb, got back in, and turned the key-dash lights, but
no turnover.  This has been the symptoms all along.  Not that it takes
too long and the battery dies, but that it will start completely fine
for a while, then will not start at all.  When in the process of
troubleshooting, this is very aggravating, as it takes three hours to
keep starting it, tweaking things to get them just right, then try to
start it again and it won't.  Wait a half-hour, and it will start
again!  If it starts again, it will once or twice, then nothing.
So far, I have changed the starter selenoid and ignition switch.  Twice,
once about three months ago when I was playing with it and once today,
if I jiggle the column/shifter back and forth, it will work-but NOT
everytime!  I wish it would, as then I would feel pretty sure that it
was the neutral safety switch or something.
When I still had the steering column hanging down, and was moving the
ignition switch manually by hand and screwdriver, this never happened,
but it happens so periodically, that I hate to drop the column and keep
trying this method until it fails.  It did have the steering column
changed at one point, so I keep thinking that maybe there is some minute
difference in the mounting of the ignition switch on these columns, or
that the rods from the key switch to the relay are minutely too short.
Of course, could it be the starter itself?  I don't tend to think this
is it, but then again, you guys know that I don't tend to know squat!
I am going to go out right now and buy new battery cables just to
eliminate that possibility-they are old and kind of frayed in places,
but why would it start so well sometimes and not at all others?
Any other ideas/suggestions?  I am really getting frustrated with this
thing, as I keep "fixing" this problem, then working on something else,
and as soon as I have the other things ironed out, this starting problem
always pops back up!

Thanks for any help!

Michael