Below I give a quick overview of a recent Moxon vise build. I thought I might be able to add to common knowledge by sharing the parts list, since that was a fair bit of annoying work to figure out, so I'll focus on that rather than the design and build. Coming up with cost-effective ways to get small amounts of hardware is tough! If you have better solutions to this specific problem (hardware for a Moxon vise) or to the general problem (cost-effective access to small amounts of hardware), please do share.
2 x veneer press screws, ~$20 each w/ ship (e.g. here, here, here): $40
3 x bronze shoulder bushings, ~$5 each w/ ship (e.g. here): $15
2 x steel washer for the bronze bushing to bear on (e.g. here, but you end up with 50): $15
2 x clamping collar to keep front chop moving outwards when unscrewing the vise (e.g. here): $15
Approximately 12' of 5/4 hard maple: $varies, I can't recall
Leather scraps to line jaws: $10
Total: ~$85 in hardware plus the cost of wood, leather, glue
The parts I used required some modification. You must remove the swivel pads at the end of the veneer press acme screws (easy on mine, which were Lee Valley), slightly enlarge the ID of the bronze bushings (dowel with sandpaper), and slightly enlarge the ID of the washers (dowel with sandpaper again). I'm sure it'd be helpful to future builders to have parts that just worked! Part of the problem was that the (discontinued?) veneer press screws I had from Lee Valley were an odd OD. Finding a bushing with a larger shoulder would also be helpful, and could even eliminate the need for the washers.
The design could, I think, be improved with a thicker front chop but it works just fine as-is. I've planed a significant belly into the front side of the chop to account for bending. Aside from being stiffer, the thicker front chop would give more registration surface. Following the thoughts of Derek and likely others, I've refrained from putting a chamfer the length of the front chop (this also gave an opportunity to practice lambs' tongues!). Thanks again to Derek (if I recall correctly) for suggesting the little shelf on the back (it gives a place to clamp a pin board when marking out, among other things).
The veneer screws also aren't a super close fit in their nuts, which leads to some slop in the vise. This, coupled with some slop in the fit of the bearings and screws in the front chop, allows for some racking as you open and close (which is a good thing). The front chop does droop as it's opened more and more, and this could be avoided with a design that fixes the threaded rods and uses nuts at the front chop (a la Benchcrafted?). However, this means rods sticking out the front of your vise. Looking back, it may have been smarter to just pay the $150 for the benchcrafted kit. This solution works just fine, so it's hard to tell.
I believe there is 25" between the screws to accommodate a 24" panel with some room to spare. The jaws are roughly 6" high.
A sketch of construction, without further ado:
An in-progress trimming shot with ryoba
A close-up of the hardware:
Sketching out chamfers, etc.:
A shot that gives you a good idea of the cross section of the rear of the vise:
Chamfers / lambs' tongues all done:
Here you can see the nuts for the veneer press screws mounted in the back of the vise:
After some Tru-Oil:
....and finally, with some leather (applied with Weldwood contact cement):
Hope you enjoyed,