Gday fitchaj,
I too am enduring the lengthy lesson in patience which is waiting for my Cat H license. Into week 9 and not even seen the ID check come through yet.
My wife and I went down the same path as you and were pretty keen on the black mamba. Really nice bit of kit and checked one out a few weeks ago. As im sure you know, its lower is a polymer ruger Mark 4 22/45 frame. So its got the nice easy take down button, compared to the scorpion which is the similar fun and games as the Mark 3's etc. Here is a really good vid if you haven't seen it yet about doing the takedown and assembly of the scorpion on youtube…
https://youtu.be/jfDa-euWr8gI eventually decided against the black mamba cause I really didn't want a polymer gun and we ended up getting a ruger mark 4 target second hand which had been tricked out with a lot of tandemkross gear. You could make a Franken-quartsen with after market parts slowly over time.. it would be more expensive that way but a fun project in my opinion.