Chet-
There is going to be a lot of disagreement with my opinion on LED bulbs but here goes....
I have used them on my '35 and in my opinion they are a waste of money. The disadvantages are many. First they are very directional. Meaning , unless you are looking directly at them you don't get the affect. It is like a rifle shooting a bullet. Unless, you are directly in line with the barrel there is no physical affect. Whereas, an incandescent bulb behaves as a shotgun. It gives a wide spray of light which is visible from several angles. Second, the LED for stop lights require a super-sensitive brake light switch to activate. I (and others) have found the "normal" hydraulic brake switch do not work reliably with a replacement LED bulb on early Ford applications. I have heard a "scientific" explanation for this but it is too early for me to recall (6:00 AM)!
Third, the bulb color is critical. If the light is going to go through a red lens (such as a stop light) the bulb color must harmonize with the lens meaning red lens require red LED. This is not a problem with the right tail light but doesn't work well on your left light which must serve as a tail light and a license plate illuminator. which requires a white light. Finally, as tail lights, the lights didn't seem to be any brighter than my regular bulbs. Again, this is my opinion with only one car I tested them on ('35 Ford).
The one good thing about LED is the power draw is virtually nil.
This is the LED bulb source I used:
http://www.superbrightleds.com/other_bulbs.htm
If you are looking for a safety option, I would serious consider a "third light". This is a source I used on my Model A and my '50 pickup:
http://www.jandlenterprise.com/products/products.htm
Tom