1750/2L, Spica & brakes

["C. Peter Audet" <paudet@domain.elided>]

 Hi, gang! 
 Do I have it right: 1750 head has a triangle mark on front and 2000 head
has a square with a diagonal line? My '75 GTV had the engine replaced by PO,
appears to be 1750, based on above. My '74 GTV seems to have the 2000.
 My 1750 has the later 3-temp switch on the Spica, the thermostatic actuator
is present but a cable runs from a spring-loaded pivot on the SIDE of the
Spica unit into the cockpit, near the driver. I presume this is to remedy a
non-functioning TA, any ideas on who made it?
 My 2000 does not have the 3-temp switch on the Spica, the thermo-act is
disconnected and a inline spring-loaded cable runs from where the TA used to
be attached to the Spica unit into the cockpit and is attached to the
"Throttle" lever to the lower left of the steering wheel.
BOTH Spica units have the fuel cut-off solenoid...
Are either/both of these the Shankle Sure-Start gizmos?
 Why do these cars have the "Throttle" lever, if the fuel injection, etc. is
supposed to automatically take care of idle?
 Now, on to brakes! The '74 had the brake lines drained at the calipers to
un-seize the brakes. This worked fine, however the pedal is very soft. What
should my first step be: bleed the master cylinder, since the fluid level fell
so far, or check the booster for leaked fluid? (Yeah, and how do I do the
latter?)
Winter projects shaping up nicely, nothing like a good heater in the garage!
Peter, London, Ont.

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