I think there are plenty of guys out there that love the 70's and 80's machine but get a bit scared by all the gizmos and gadgets on DMD machines. Something like a late 70's Bally machine is very easy to strip down and clean compared to a DMD machine and the artwork is second to none.
The boardsets are already out there e.g. Alltek, Pascal, Rottendog and the like. Produce a machine using these or similar boards with a sweet looking backglass (not translite) and playfield and I reckon you'd sell enough units to make it worthwhile.