In case anyone is wondering, I was unable to locate 14mm t-slot nuts with 1/2-13 threaded holes, at least from the common suppliers.

Running an extended break-in cycle is well worth it, BTW - a cyclic gear noise that was quite prominent during the first few minutes was practically gone by the time I was done. The downside, of course, is that I wasn't able to get my vise mounted this weekend due to lack of hold-downs, so after I ran the mill through the break-in cycle I was not able to actually try it out. My guess is that the G0484 table is actually machined to metric specs, which end up being close enough to imperial spec that Grizzly can get away with selling some extra-narrow '0.55-inch' t-slot nuts to make up the difference. It turns out that the G0484 slots are actually 0.55 inches wide, which seems like an odd number - unless you convert to metric and realize that this is extraordinarily close to 14mm. Because the catalog page for the G0484 lists the slots as half-inch, just like the BP clones, I assumed that the standard kit would work fine. The common 1/2' clamping sets come with t-slot nuts which are made to fit 5/8' slots. Typical 'Bridgeport' slot width is, as far as I can tell, 5/8' (0.625 in). I got my new G0484 wired and powered up this weekend, and in the process discovered something: it has a decidedly non-standard T-slot width.

Drill press t slot bolts