hi lee,

i have and use one of these old cameras and recently just took it apart and worked on the shutter.
ive worked on series D + speed graphic shutters for a long time but this one not as often ...
i was a little rusty, even though the last time i took it apart ( 2 years ago? ) i was helped by a retired repairman,
this time, i was pointed in the right direction by another helpful person easmithv mentioned ( shutterfinger )
who sometimes is active here, and is active over on graflex.org. i had a few silly questions but i pretty much remembered what i was doing ...
once you fiddle with one graflex shutter, the others are pretty easy to mess around with.

to get you in the right direction ... there are a few threads there if you use the search bar, and type in "3A" you will find them.

the 3A is a fun camera once you get the hang of using it.
have you been able to wind the shutter or trip it ?
these cameras are kind of finicky, and they are a little different than most.
FIRST --- the front standard NEEDS to be out of the camera on the track for the shutter mechanism to work.
there is a little button on the right side of the top of the camera that unlocks the front. its like a speed graphic type thing.
lock the bed down, unlock the front standard and pul lit out of the body, you will notice something behind it will kind of push it out
while you pull. once it is out of the camera you will be able to fiddle with the mirror, wind the shutter &c ..
the mirror is already up when you pull the lens out .. for the standard to be nested inside the camera, the mirror has to be UP ...

when you pull the front standard / lens out onto the tracks, you will be able to wind the shutter.
you should see in the little window near the wind key what tension it is on and each number you should hear a "click"
when the shutter is ready. there are a handful of settings, and a lower spring that makes the shutter travel faster or slower
the "1" setting is the slowest ... on the chimney hood you should see all the speeds ...
there is a tab you depress to pull up the chimney. to put it back in, like the front bed
you depress the struts to unlock them it all folds up nicely.

unlike the series d + b &c, your camera probably has a little wheel that turns to T and I, no sliding bar.
if you have it on T when you release the mirror ( button/lever on left side of box ) the mirror will go down.
on T the shutter won't engage it needs to be on I to do both .. turn the wheel you will see the I and when you depress the shutter release it trips the mirror AND shutter.

if you have the back of the camera open ( spring latch on the bottom ) you can see how when you wind the key the shutter travels.
you will also see the mirror go up and down when you press the little lever. as dan mentioned you won't be able to wind the shutter
with the mirror down

if the little wheel is on T you can still manually fire the shutter, once the mirror has fallen down .. depress the little bracket near the winder
the shutter release is there and you will hear the shutter release.

have fun with your new camera !