Miche Primato

I had some Miche Primato hubs. They have a reputation for the flanges to go bang. It happened to me once and two others I know of.
Also, the bearings were OK for a while, but they weren't that good. Especially in the wet. They made a right racket for some time and developed quite a lot of sideplay.
If the BBs are the same quality, I'd avoid unless desperate. They maybe not the worst that money can buy though.
I'm very fond of my cheapo Campag sealed BBs. They are the best BBs I've ever used. At least the Miche BBs are pretty cheap.
If it's giving you hassle and you ride a fixed, I wouldn't bother trying to sort it out when you can buy a decent Campag one which if my experience is worth anything, will be very reliable and last a very long time. Easily 20,000 miles.
No, it doesn't have a lock ring on either side - imagine a regular cartridge bottom bracket, but both sides are like the left hand side.
The first time mine came loose I noticed because one of the crank bolts started touching the rear fork where the entire thing had shifted left.
If you can't use lockrings, then I'd use some threadlock. If that doesn't work, I'd bin it and buy a Campag.