A few years back I was able to hand pick a number of the SOC contract WASR 10/63's bright back from Iraq & Afghanistan.
Utterly
beautiful, naturally aged & worn rifles if a do say so myself.
The problem was that they looked like poop with non-appropriately worn magazines.
I tried a number of suggested methods and all as looked as fake as a porn star boobies.
So after I gave it some thought, I came up with a method that looks awesome and not at all fake.
I took a 5 gallon bucket and filled it about half way with
50d nails.
I took a brand new Romanian magazine and used multiple layers of electrical tape to cover the feed lips and reinforced area. I then took mueller tape and randomly wrapped sections of the mag body, avoiding the common wear area on AK mags where folks tend to grip.
I tossed it in the bucket cover it with nails, threw in some gritty sand, then put it in the bed of one of our ranch trucks. After a week of bouncing around it looked great! The mueller tape freys so there were no hard lines, I removed it then replaced it different sections. Tossed it back in the bucket along with another few handfuls of gritty sand.
After two weeks it looked spectacular, and utterly indistinguishable from naturally aged, highly used AK mags, and it matched perfectly. I ended up doing more so each rifle had a matching mag. I also experimented by spraying them with oil every other day, this helped the grit stick and gave a much more realistic finish.
A bit fiddly but they look nothing like the ugly, fake BFPU finishes many are applying now a days... and charging money for.
Something as small as you have, I would use an empty water bottle.
But the ring in with some gritty sand, a few nuts and bolts, then let it roll around for a week and see how it looks.