Secondly, after setting the proper piston at TDC and backing it down a bit, it doesn't seem to matter how much I rotate the points backing plate, I get no reaction from the test light.
Something to bear in mind is that when setting the timing, you should ALWAYS rotate the engine forward to get to where you want it to spark.
Otherwise, all your backlashes can accumulate, and the timing will be in nowheresville.
And until you can get your timing light to show something, its not going anywhere either, is it !
Obviously we can't see what you have done, but if you open the points manually the light should come on or go off.
And until it does, you need to work on it. Having something earthed or not isolated is a common cause of this
- but we can't see what you have done ...
Have fun !