Good question! Good thought too, but I'm not sure I've ever seen anyone use a common point and just put terminals on the wires for future replacement.
Guess they figure that they'll never ever have to mess with those again. But with the dash light bars, there is no simple bulb to replace, so a connector isn't a bad idea.
One possible method though, so you don't have to worry about something touching and shorting out a positive power terminal under the dash would be to use a multi-wire connector with jumpers.
Or just one of those old-time "Radio Shack" terminal strips. I know they weren't exclusive to Radio Shack, but that's what a lot of people know them as, so it's a description that works most of the time.
The terminal strip is not protected either, but doesn't have a single stud sticking up into harm's way either.
Maybe there are versions of it that have protective covers? GM makes those 5-post buss-bars that I use for various things, but they're big and way overkill for little 20ga wires or whatever the illumination is.
Anyway, good luck. Maybe someone has used some sort of protected power strip, but I'm thinking a small Weatherpack connector with one power in and jumpers to the other three or four wires would do it.
Or are you thinking of all the dash bars, AND all the bulbs in the cluster?
If this is your '68 though, you would not have light bars unless you converted. So are you just speaking of the cluster illumination? Usually not a big issue for most as they're already spliced together into one wire to the switch.
Are you wiring from scratch, or using a kit?
Good luck.
Paul
We went nuts on lots of circuits... used 3 of these Eaton boxes. They hold both micro fuses and relays. Worked out pretty well... 
