I won't be building any soon. Got far too many other things to do, but a few doodles would indicate all the bits would fit in, however it would need a good few calculations to see what kind of forces would be involved and if they're acheivable.

Thinking outside the box a bit, use a set of ball bearings that go under a pull stud, that are then forced into place by a spring loaded outer tapered sleeve. The spring could even be assisted in locking by air pressure, as once the tapered sleeve is pulled up, using appropriate tapers it's essentially self locking.
Now for release, you have another set of bearings on top, that also run against a taper, but this taper when moved to release, forces the bearings between the top of the pullstud and another taper above the pull stud.
It would be quite a complex setup, needing hardening and grinding of various parts, and that's once you've figured out how to machine all the various bits to ensure the balls don't just drop out.