Nice gun. I can't tell you much about the builder but I'm sure someone can.
The rear sling mount is nice, wish mine had it. I also like the look of the Ultimak and will be getting one myself.
As far as the stock cheek piece, spend the extra few bucks to get the 1 piece welded unit rather than the bolt on model. It's very easy to install and is super strong and looks much better. It's also carefully shaped to allow safety lever access while folded.
If you get a chance could you post an up close pic with the handguard removed so we can see how it was adapted for the AMD?