That leather might be to tight grained to get the desired effect. But 60 grit might be worth a try.
That gray color is from the tanning/dying process I believe. Your leather might not have them gray tones under the black like the other belt you pictured.
It is a tandypro pattern 3600-02 wallet. I dont know if it's still available.
It's a makers leather supply pattern, here is the same pattern & it is still available.
I was going to reccomend Chicago screws, but I was beat to the punch line.
You could use nickel silver cutlery rivets. But you would need to buy the long ones & then cut them to the length you want/need.