Yes, I have a thing for those robot ladies

If you look closely at the back-glass pics I posted you'll see I already have the third monitor. Its this one:
GeeekPi 7 Inch LCD Screen for Raspberry Pi, 1024x600 IPS a non touch screen, small display.
Here's some more clarifying pics see...
firstly flooded with light so that monitor can really be seen. I'm just testing it at the moment and configuring Visual Pinball and PinballX so that the new 3 monitor setup works properly.
In normal low lighting that looks more like this:
That image of the Mech-spider is actually a video. Final cabinet reveal will feature all display art (video or static). I designed the spider, which is a 2D feature of the original 'The Web' pinball artwork for multiple purposes including animation and 3D printing. Here is the master:
3D printed it can be posed as it has moveable joints. I'm tempted to print that fellow and perch him on the top of the Back-box

Here's a closer look at the 3rd Monitor displaying the DMD for Attack From Mars in normal lighting:
The original back-box front frame will have to be re-done to fit the new speaker/monitor setup. I'm fine with that. There's a few things I'd like to improve in the new version.
Overall I'm very pleased with the direction this project is taking. There's just so much to learn about the emulator and front-end software setup, especially for optimal game play and virtual pinball experience.