Thanks guys for all the positive feedback
The parts from Ultimarc arrived today, hopefully I'll get the control panel together over the weekend and have some pics for next week.
IG-88 & jcroach: I have all the dimensions on paper. I'm still confirming all my measurements and transferring them to the PC, when done I'll post them here.
hbm*rais: I'm planning on a 2-player panel with 6 buttons each (it's a bit tight at 530mm x 120mm)
stuzza: Your cabinet actually inspired me to start the hobby again. I was considering replacing the original control panel to something like yours but decided to keep it as original as possable. (I may change my mind yet as 2 players with 6 buttons each is going to be a tight fit.)
Kangum: I have since squeezed in a coin box and modded the mech's to take the BYOAC tokens. Works a treat!