Rather than look for an existing pin to add to my herd, I have this desire to custom design and build my own pin, so I need some ideas about the basic logistics involved.
I figure that the best way to do this is to do it as a conversion from an existing SS pin, but with a different game ROM. As I understand the early Bally SS system (and have 3 of these in the herd already), and new parts (including boards) are easy to source, this would make the basic logistics work out the easiest, although if I want to get something more advanced, I could do the more advanced Bally system of the early/mid '80s. Based on the problems I have encountered with Williams System 11A (Fire!), I want to avoid that. All I would need to do it pick up an old, cosmetically ugly pin that I know to have a maximum amount of wires for switches, lamps, coils, etc. (where could I get that information?) and strip off the playfield, and I would have the basics in place (I might move around the playfield items, but that could easily be spliced in).
So here comes the hard parts:
 Game ROM for the MPU. I am not sure how this would be done, but obviously there is some Master IC(s) that would need to be installed. I'd also like to be able to use COTS remanufactured boards like the Alltek MPU and have it work with that, including being able to use the 32 board switch settings. I am an "early retired" programmer, so writing the code for the IC would not be a problem (what language could it be, BTW? Assembly? C?), but then I would need some IDE and that would make the proper components that could be programmers into the Master IC, and some hardware device that would physically load the Master IC with the component. I'd also like this Master IC to be something that could be rewritten. Also, I would tend to think that the code for existing pins is accessible in the public domain (i.e., for Bally).
 Sound board ROM. If I go early Bally, this wouldn't be an issue, but I think I want to have much more ability to do sounds, being able to do add in snippets of human voice or synthesized MIDI tracks, etc. I figure that 8-bit digital audio should be good enough. Again, I would need to somehow program the Voice IC(s).
 Backglass. I would come up with an easy design, but then I would need to get it printed somehow. I supposed that BG Restore could simply printout as per a PNG file I would supply, or if I wanted to go the translite route, it seems that I could get a local printer to do that, in which case, I'd like to know what kind of "paper & ink" would be used for this. (This would be handy in me replacing one of the translites I currently have, as I could scan that and reprint it.)
 Plastics. I think I could get someone to print this out, so it wouldn't be an issue, but I'd be interested in anyone that has done this before and could do a proper professional job), and that could do a one-off.
 Playfield. This is the toughest one. I know that CPR and I think someone else is capable to doing a professional job of milling and painting, but I wonder if the costs for doing a one-off would be prohibitive. I presume that I would simply supply an engineering drawing of the playfield, detailing the location of inserts, screw dots (I'm not sure of the terminology; this would be the very small & shallow hole where a screw would be installed), and of course the artwork (which is going to be quite generic, although with the standard test associated with a regular playfield). As for the design, I am looking for an overall design that would allow for different orientations of posts & rubbers, so I need to think about that; if anyone has any pointers
I should say that part of the goal of this is to be able to change the game essentially by swapping out a populated playfield (and the associated wire harness) and the MPU & sound boards (I think I would just have separate boards for separate designs rather than fools around with popping out ICs). The artwork for the backglass and cabinet would stay the same. Something of use here could be a COTS storage box for a playfield.
I also plan to set up a simulation of the game on VPinball before I get to the "cutting" phase of the playfield.
So that's it. I'm open to any & all suggestions.