I think keeping this thread updated will be just fine.
Something to consider: When you convert the bridge from 8-string to 12-string, the second octave E makes it necessary to mount the bridge slightly off-center in order to align the strings evenly from side-to-side on the neck.
It's a small, but very important detail to keep in mind.
Thanks for the information about the bridge, and for your input about updating this thread, as opposed to starting a new one.
Regarding the bridge, this one is wider than the one already on the bass, so I would have to move it to center it. At least that's what makes sense to me.
I do have a bridge question. The stock bridge is set at a slight angle, the E is tilted closer to the bridge, the G closer to the headstock.
What's the purpose? Is it because this style of bridge has less intonation adjustment as, let's say, a stock Fender bridge, so the angle is necessary in order to
allow the saddles to sit in their "sweet spot", to give them the adjustment they each need to properly intonate the strings?
Also, I tuned up the main E A D G strings on the stock bridge, (the octave strings I tuned a full step below where they should be to keep the tension down) then intonated the E A D G strings.
A the angle, and position the stock bridge now sits, the E and G saddles are basically set almost all the way back in order to intonate those strings. This makes me figure I need to set the new bridge,
which is a similar style with a similar amount of room for intonation adjustment, a bit further back than the stock bridge to give me a bit more adjustment room. Does that sound correct?