Turns out that the correct part number as of this writing is indeed the 34908-MG9-951 that redline919 listed. It's smaller than the 194 equivalent used everywhere else in the instrument pod (34909-KW3-003) and is a Toshiba wedge base bulb. It's rated at 12V 1.7W. The 1.7W bulb is a special output unit made only for the Japanese motorcycle makers and is possibly Honda exclusive.
Now, here's some fun info for those that want to replace these with LEDs or needs these right away. (This isn't entirely original research.) The guys on the Honda NC30 forums figured out that this bulb is the exact same physical size as an old style Lucas LLB286 - the only difference is that the LLB286 is a 1.2W bulb and as such is somewhat dimmer. A cross-reference at Don's Bulbs shows that the LLB286 is exactly the same as the relatively commonly available 2721 bulb. Those are sometimes available at Walmart and usually available at better stocked auto parts stores.
It turns out these are described as W2X4.6D bulbs physically (check Don's Bulbs link above for full specs and dimensions) and you can get very bright (brighter than even the stock 1.7W bulbs) in this packaging.
The full dimensions of the bulb (if the DB link is dead) is T1.5 W2x4.6D - the bulb is 5mm in diameter and 18mm tall. That should be enough info for anyone wanting to do LEDs for this application.
The last time I had one of those bulbs go out and in trying to get a replacement found they were very pricey: three bucks for a bulb that looked like it would cost 30 cents. Forget it! Fortunately I already had quite a few soft white LED's that were prewired for 12 Volts DC for another project (Picture 1. Note the ballast resistor covered by the heat shrink tubing.), so I cut the wires attached to the original socket, worked the clips out of the rubber socket, and inserted one of the LED's wires into the holes vacated by the original wires (picture 2) until the heat shrink on the wires came into view. This sealed the holes. (picture 3) All that was left was to splice the wires to the original instrument loom: Red to the Orange on one side, and Sky Blue on the other, and black to the Green / Black ground wires. Put the cover back on and Bob's your uncle. The light is a little brighter, and they will never burn out.