about hydraulic woes

On my 83 the hose pulling fluid sits about half up the brake fluid
reservoir so even if the clutch master cylinder drains it can pull
enough fluid out of the brake mc to give problems - unless you are driving
on a 30 degree slope or the like!

Sounds like your switch just rusted up - nice price on the replacments!

I rebuilt my clutch mc and the slave cylinder in the last couple years -
the bleeder on my slave snapped but i 'muldooned' it by drilling and 
replacing with a SS cap screw. I added checking brake fluid level to
me weekly check list but after six months of no leakage i declared it
to be a permanent fix   :-)

Note that i wouldnt dream of such measures on the BRAKE system

REPLACE all that ugly old brake fluid - my guess is that is what
made your switches freeze up.