Another step I made differently this time was using Chris Schwarz's rabbet for the tails. I used my flat ground tablesaw blade to make a rabbet on the back of the tails. This way I could firmly seat the pin board in place and make sure it was lined up with the tail board.

I must say it worked far better than I had initially expected. I had no problems with the boards sliding on each other as I normally do, and matching the baseline from the tails to the pin was so easy I couldn't believe it.