Hi Alan. Your reply sort of imies that perhaps your interior is “not all there” which would explain why you had not seen the “english-metric” slider button.
Do you need some help sourcing one? Where I live in canada, alberta, i always call Jason at Western Corvette. Im quite sure he will have one for you. Unless he is able to verify multiple years share the same part, insist on one from an 86.
If you are in Ontario or east, there is an outfit called “northern corvette” ive not dealt with them but ive seen them mentioned as well.
As for the question on the yellow button in the center console. I suspect it one of three rear hatch buttons. Though i have to say, im not 100% on if there was a center console mounted yellow hatch release button on the early cars. Ive sold all my early cars and cannot verify. Does the yellow button look like a factory piece? If yes, it would likely be the hach release. Though my memory is that they are installed at the forward position. Not rear.
Im happy to help and assist. I had my 86 couple right down to the guts at one point. If yes, can you post a picture set of the interior of the car so i can get an idea of the scope of your project?
Cheers.
oh, and there should also be slider buttons (they slide downwards) on the rear face of both door cards. These also release the hatch.