Hey Dale,
I didn't get very far with it... Vindoline generously sent me a micro board which I soldered up and made into a breakout board of sorts, but something was up with the processor and that board wouldn't run. I'm not sure if I fried it doing the soldering (I like to think I do decent solder work!), or if it wasn't working to begin with... but I couldn't get a pulse out of it. I've since been distracted with other projects but would like to get back to it.
Two other "display rework" options did occur to me:
1. Instead of using an oled - that requires something to read/interpret/translate the current lcd drive signals - it might just be easier to do an smd led display made out of pcb layers. Modemhead wrote up a post on his site about a meter Dmitri reworked with LEDs, but my idea is to use the pcb manufacturer to make a 3 board display sandwich... bottom board with pads for the leds/segments, middle board with routed slots for the segments, and the top board for a diffuser mask. Then I'd have to solder in a bunch of leds and maybe add some glue for extra diffusing, but I bet it would work. I saw somebody build a 7-seg clock display this way on hackaday.
2. Discard the current micro board and build/program a new one that drives an oled instead, but that would require reverse-engineering the signals to/fro the mac/micro and then re-writing the software to do all the calcs and tests and gahh I've already got a headache. I never did ask Dave Taylor if the source code for the micro chip was ever found (if it would even be able to be shared). I think he mentioned it the amp-hour pod-cast, and that his friend that wrote it had unfortunately passed.
I do love these meters though... and I still think it'd be cool to have a cheap easy display replacement.