These studs are from eBay, I just searched for ‘antique gold pyramid studs’ and these came up. They were £1.99 for 50 (but actually there were 75) which I didn’t think was too bad!
The studs are so easy to attach, you just pop them in place, push the pointy bits through the material and press each point down until they’re flat.
I didn’t want too many studs, because I think with the checks it could look a little OTT. I decided on a small V shape of studs on the collar and three either side each button on the breast pockets.