Looks FANTASTIC and I have to say, when I started work in the amusement industry this was one of my favorite machines - in fact, Williams machines of that era were by far and away the best playing games.
What are you doing for boards Nino? You mentioned that the machine had none?
I have a box of SYS 4/6 boards from the old days. Labels on the boards are "Laser Ball", "Disco Fever" and "Phoenix". I have a few Displays and the rest of the boards except a good MPU board. The MPU board is in really bad shape. I've already contacted Ken (Skybeaux) for one of his repaired and tested MPU boards to slot straight into the machine. Gavin (Retropin) sent me a Master display driver board as a spare, so I'm hoping to make one out of three.
I was thinking the other day if you would be making a replacements MPU, as there are no repros ? The Rottendog is expensive, but covers the MPU AND Driver board. I think a repro MPU board would be a great idea,