OK I just tried several bulbs and the brightest and best looking was a # 70 rated at 150 mA.
Here is a link to a page that shows a #73 and #74 lamps like used in GM dashboards.
I tried a 73, 74 and a 70 and all three are bright enough to back light the display in sunlight.
Just bend the leads 90* to the body of the bulb drop it in the hole and solder.
#37 = 80mA.
#73 = 80mA
#74 = 100mA
#70 = 150mA
The actual amp draw will vary from one lot of bulbs to the next.
I think wally-world sells one or two of these number bulbs (lamps).
Now if someone who is good with a camera like Sonoma_zr2 will give this a try.
I never thought about soldering the bulb in till he posted the picture on previous page.