If you're asking about the attatchment, you should be able to just sew it on if you're inventive, but I think they're "pressed" on, like eyelets. Not sure though.
Maybe you could make one of your own if you're real handy? They're a rather simple construction, but they're more easily bought than made ofcourse. I've seen them loose now and again. They're just two "bows" attached with a screw at the edges (kinda like glasses are held together, you know), then the ball things in the middle have to be slightly not-right-next-to-eachothers but not too opposed to eachothers either, so you'll be able to do the snap-thing. Some trial and error should let you fix that bit. You could probably manipulate plastic or wood for this purpose, but it would wear out very quickly, so it's better to make it out of metal.
And easier just to buy it.
And then you could ask in the store? If nothing else, just buy a coinpurse and rape it, attatch your cloth onto the one that's already there.. but you should be able to find it in some sort of bag store or craft store... I'm not sure, I think our major hobbystore has it here though.
Oh, and when making a coin purse out of a tee, make sure that the interior of the purse is not stretchy, cause it might grow to no end from heavy coins