Aaah, these ol'chestnuts. I had to put my research on hold for the X-Wing and Y-Wing control sticks (and entire cockpits) due to my
drives getting trashed at that time and a lot of info lost - then a few weeks later other stuff came along so I didn't get to complete
the projects. I'll jot down the thoughts I had on the parts and see if that helps.
Calculator
You are right, of course, on the Exactra line of calculators for the Y-Wing stick (check the indent hole between 6 and 9 and X,
vissible in the screen cap) but I think there are actually two different variations of the desktop calculator in use, possibly even
three between the X and Y Wing pits. One Exactra type as you've found, one that could be more along the lines of a Casio type and
there is.... another - in the footwell of the X-Wing (cos there's always "another" lol). Exactra seem to use muted / drab colours -
olive, orange and possibly light blue keys (look close at the long keys in the screen cap, blue and pinky orange showing through).
Updated - I've just seen a pic of the underside of the X-Wing targeting computer, may or may not be a calculator at all!!! This
changes what I was typing below. Again, cos.... Star Wars....
On the side of the X-Wing targeting computer there's a bluey-greeny zero key with a Casio style profile - but you have to check all
the Casio types because there are very slight differences in the flared base end angle (see the pic for a tiny difference). Very
differnt to the Exactra straight edge style. But here's where it may get a bit odd.... The Y-Wing calculator pad seems to have an odd
shaped key in the 'number 9' possition (with the white base), it's more like a Casio key and a little bit shorter than the rest. Maybe
the calculator pad was damaged or the key was indeed swapped with a Casio key - but that was just a thought from back then.
Now, the Casio type looks a lil more like the keys under the X-Wing targeting computer, which I think are the other two long keys
(the + and -) and two numbers (being a Hendrix fan obviously it would be a 6 and a 9, but I don't mind). And this is where my mind
went into 'What if....' mode, just before the great crash.
Control Stick
Why is this clip of an odd looking stick pasted inbetween the X-Wing run shots? I don't know the filming dates or times to any of the
movie scenes, so I'm wondering what if this stick was from an extended Y-Wing run on the trench that didn't make the final cut? Or,
maybe this clip was filmed in the US to add some extra tension as an after thought. We know the small red button looking part was on
the Death Star canon trooper helmet and that scene was filmed at the LA power station.... If it was filmed in the US then that would
help explain the use of an Exactra desktop calculator, being more common there, and a cheapish Casio in the UK. The turntable discs
and panel indicator switch covers where everywhere so they would have been shipped with costumes and props for pickups.
The stick itself reminds me of something but so far I can only guess its uses. There was an early 80's UK based sci-fi film that used
two similar grips to control two robotic arms that moved liquids or something around a secure room in a laboratory situation. Long
poles extended from the tops of the grip - like where the silver disc is covering a wider circular area and maybe a hole. It will take
some time to find that film again lol.
The trigger may have two uses, going by where that safety pin is located. It may be dual-use, as the pin is very far forward on the
trigger, it could be that a short pull operates a temporary manual action - then, remove the pin to activate a secondary sustained
action, where the part is pressed in, then you fully pull the trigger and the switch is held in by the body of the stick's top. This
action reminds me of something that could be used for filming or lighting like on an early belt operated steady-cam. The horizontal
lines on the grip part remind me of a large flash or strobe-flash light handle. Other uses could be for an aimers control in a plane
turret or, as mentioned above, for construction hardware like a crane. But the horizontal grip lines sugest the part is hand-held
freely rather than something that is push-pulled.
I didn't get much past these ideas, so the hunt continues.