What did the finish look like? Did they have any optics on them before they went to the 5.56? Any help is greatly appreciated!

Roger that. So a glossy spray paint would work then. I'll probably seal it with something like acra-coat. I'm curious about that PK-AA that Zen had on his sight. But I'm still interested in what the Bulgarians might have used then.

For reference, here is a kit I used to have.

Both the factory finish, and what arsenal uses, is paint. It's actually the topic of a lot of complaints when someone tries to use brake cleaner on their $1000 arsenal AK.

Parts kits could be anything. Parked is pretty common, ORF was well known for very grey park jobs. Gunkote, duracote, and molyresin are all pretty common. I've personally never seen a oxide/blued kit build, but I don't doubt it's been done. I'd like to see pics of a blued 74.

The problem with most spray paints is the level of gloss isn't "right". Either the finish is way too shiny or it's too flat.
In most cases with spray paint you get gloss, flat, or semi-gloss. Even the semi gloss is usually too shiny to look right.
Another problem with flat paints is they tend to get shinier in areas that are handled, and those areas give an ugly blotched look as the flat paint wears.

A better option is one of the Lauer Duracoat finishes. Not only are they a lot tougher and more durable, they offer a wide variety of "black" colors and different levels of gloss.

If you really want to use paint, I always used Rust-oleum oil based paint in cans. I mixed a small amount of Gloss in with flat black. The gloss "cut" the flat to give a finish with just enough gloss to prevent the handled areas from getting the blotchy look, but not enough to make the surface at all shiny.
You have to experiment with the mix to get it right with no shine, but not the velvet-like surface of fresh flat black that wears and causes the blotchy look.

I sprayed it on with an air brush and baked in the oven. This makes a durable finish, but not a durable as the epoxy paints like Lauer.

Ive always had good results with Rustoleum appliance epoxy. Not sure about original bulgarian finish, but it matches alot of the Russian parts that i have pretty well and is some of the most durable paint i have dealt with.

My neighbor owns his own firearms refinishing business, and has done several projects for me in the past. He also happens to be a fan of the Kalashnikov platform. I recently asked him about the factory finish that comes on the Bulgarian, and Russian rifles. He told me that to the best of his knowledge, the factory finish from both countries appears to be an automotive grade black paint, or something similar. For what it's worth... He treated his Arsenal SGL 31 to a fresh Cerakote job immediately upon getting the rifle. I am probably going to have him do the same with my Arsenal SLR-107CR when I get my form 1 back from the ATF.

Mines being done in Satin Black as we speak. I'll post pics ASAP.

Got it back today.

It's beautiful. I will update this post when I get off work tomorrow morning!

The quality of the pictures doesn't really do the finish justice. It's not glossy, but not flat either. It's ideal for me.
Enjoy......but sorry about the picture quality