I dunno if they're "OK" to reload with. I do know that I've reloaded cases like that, and they function. I'll run them through the resizing die a time or two, giving the shell a half-turn in between. What's left of the dent should come most of the way out when you bell the case mouth. As I use lead bullets for my loading, I bell all the cases, to minimize lead shavings from seating the bullet, and just adjust the seating die to give the round a bit of a crimp.
The brass shavings are probably be a result of not lubing the cases prior to sizing. I have found that Dillon's spray-on case lube is very effective; Lee's lube is problematic at best, and really gunks up my dies. You do have to tumble the cases after using the Dillon's though - it tends to get sticky after a while. Imagine handling cases with a light film of dried Sprite on them, and you'll get the picture.
In short, while I dunno if those are OK "by the book," I'd certainly use them. Major dents, splits, and crumplings are just about the only things that will disqualify a case for my use; yes, I'm kind of cheap.
... Which reminds me, I've got another thousand rounds I need to load in the next week or so....
[Edit] Forgot to address your second question. Unfortunately, I don't recognize the headstamp. I presume it's military surplus from somewhere, but haven't a clue where. [/Edit]