Okay, this is the mock up I made.
It's not exactly the same hook and eye tape as I mentioned before, but it is very close. And it's black with chrome square eyes.
I sewed the tape onto the fabric pieces in the most simple straightforward way. I added some multicolor sequins to the mock up for size comparison to the original. These are the standard sized 6mm flat sequins.
I closed the two pieces together with the hook and eye tape and pinned it on a doll, making sure to put a little bit of tension on the mock up, simulating the tension of a bustier/corset. While I took the picture I slightly moved my camera a bit to recreate the tiny unsharpness of the motion blur we see in the original photograph
Using photoshop I posted the picture next to the columbia picture. All I did with altering the picture, was brightness, contrast and some color changes, cause the fabric came out a bit redder on the picture than colombia's did. I then scaled the picture (while maintaining the original dimensions (no stretching the image) and then rotated it slightly to mimic the diagonal of the original.
I personally think it is a very good match. Both in look, proportions, and spacing. But see what you think.
This is shared with permission by Stefan from the RockyHorror.org forums. He debunks a long-held myth that the floorshow corsets were worn upside-down and backwards to get their unusual style. Stefan did a mock-up of what he believed were the hook and eyes up the back (not a busk), which would imply they were custom-made for the film (not bought off-the-rack) and his image lines up beautifully with screen-shots of Columbia's corset; see for yourself-