I would say you'll have to make them. Get 1/2" bolts, cut off the heads and weld short lengths of SS 1/4" rod across them.

If you going to polish them, aren't you concerned about chipping the pain around them? those T bolts hit the axle tubes when you tighten them, that is the point of the "T" in T bolt. The wings swing over and hit something to keep them from turning.

We generally just use SS hex bolts and hold them with a wrench when tightening the backing plates.