The Zastava PAP type rails are not available at retail. They were never imported.
You may find a take-off rail on Gunbroker, Ebay or an AK site Marketplace.
A modified M76 or other rail can work but not necessarily with that mount you have chosen. You would have to research that.
I installed a take-off PAP rail on a hybrid Zastava build in 5.56. I modified it and moved it forward on the receiver by 1.25 inches and used the lower front trunnion rivet. It is a much better location than the original for most mounts.
I started out using a M76 optic.,




But later switched to a Russian mount and a simple 3.5 power PU style optic.

