My suggestion of turning down the studs was based on the studs being removable from the T nut, so that the stud would be stepped to pass through the T slot, whilst retaining, for convenience, and minimum work, the original larger size nuts.
If the stud is integral with the T nut, which unless made from a forging would not be an economic means, the relief to allow entrance into the slot could be filed into the stud.
Otherwise, as Sam said it could be a case of "pulling oneself up by your bootstraps", "Dear Liza" and so on!
Ideally, if an angle plate is available, the vice could be machined, it not already, for keys, or even dowels, to ensure alignment.
My vice is not really suitable for this, hence the use of the "goalpost"
Howard.
Edited By Howard Lewis on 04/08/2021 08:35:37