G'Day Mark, I've had a couple of OEM fenders re-chromed, the original plating is rubbish, and one plater told me that it wasn't even chrome, but rather just nickel, one of the three stages in the "proper" chrome plating 3 stage process. (copper/nickel/chrome)
"Proper" chrome is much deeper, richer, smoother and shinier than OEM "chrome", and will probably last the life of your bike, so if you can get your stuff done cheaply, I'd recommend it over buying OEM every time.
You don't need to "de-rivet" your fender, and if you do and re-rivet it you'll have the problem that your new rivets will rust/corrode (depending on what you use) in time, while your chrome will stay nice and shiny. You could use stainless button head screws like Rick, but you'd need to check the clearance between your front tyre and the brace, to ensure that there's sufficient room for nuts, washers, etc.
Up to you which way you go mate, but I'd rather chrome my 30+ year old parts if they're in good condition (or can be refurbished) than buy re-pops, most I've seen have been of very poor quality. You really do get what you pay for.............
