Hmmm, on my "B", I have removed the signals, however, my 2 indicator lights, (in the tachometer gauge) are blue (high beam), and amber (oil level), someonemay correct me, but that's always been my understanding. I know the lights purposes varied and changed as the models evolved. I apologize that I haven't
read all through the posts regarding this, so forgive this, are all of  Your gauge light(s) good and working ? I've recently replaced all of mine, no more trouble after a needed  voltage regulator. They are easy to replace. Which color stays on solid ?,
if blue, that would mean high beam on my bike....

3 total bulbs, the 2 I mentioned, and the one that illuminates the gauge face....

I'll check all the bulbs, RT325. I just ordered a 10 pack of 1129 bulbs (6 volt 17 watt) and will make sure that the indicator bulbs in the tach are correct as well.  As far as the flasher relay, I put the original one back in yesterday when I was installing the new rectifier.  I'm thinking I should reinstall the one I bought from eBay seller "pobit", as his is supposed to work much better with our bikes than the OEM unit.

Are you using an LED in the gauge indicator light?

No, MarkT....just the standard tiny 6 volt bulb.  Unsure of the wattage, but definitely just a 6 volt incandescent bulb that looks like the others installed in the tach and speedo.

Sorry, jumped in here kinda late, I've posted a couple above recently....
I've got the same bike. If You haven't read them, check them.
Here is what You need....
 
12-6406 A62 6V/3W.. the small guys. The ones You ordered will be
of course, the size of the one on the right. Suitable for taillight.

Kinda hard to find, I've got them off the 'bay recently. 10 pack for $8,
Here's one for You, I should have thought to take a picture, I was having
trouble with the one that illuminates the face, upon inspection, the contact in the bulb holder was pushed into the bottom of it that it that it couldn't make contact.I tried to pull it up, but I ended up just nipping a bit of solder and placing it between bulb contact and holder contact. Just a suggestion ?...

Thanks DAILYRIDER.  Yes, these are the bulbs I have.  When I said that the indicator light in the tach stayed on solid (when I turned on the left flasher), I guess I just assumed everyone would know I was referring to the amber turn signal indicator light and not the blue high beam indicator light.  My bad.  In any event, the strange thing is that when I turn on the right flasher, the amber turn signal indicator light doesn't light or flash at all.

I just know when I did my research, as I noted in one of the posts I found out amber is
for low 2 stroke oil in the reservoir. At least in my 250 B....
More than happy to help. This is the 2nd one I've owned,
have had it 12 or 13 yrs now, it is identical to the one I had
in high school I always regretted selling.

I had to do the research, to refresh my 'ol memory-brain with what I knew with
the first one I owned, 45 years ago !!!