I'm a bit ashamed to admit it, but the ingenuity and cleverness that usually surround my problem-solving experiences (not really!) totally escaped me during my initial efforts to solve the fractured spool pin dilemma.
Here I was, whining about this insurmountable (I thought) problem, when the solution was really pretty simple. Examining the main piece of the pin that broke off I was able to confirm the stub left behind was threaded. So, after I got over my initial pity-party and I came to my senses, I used a small, round bit on my Dremel to grind a little bit of dimple on the end of the stub. The dimple would keep my drill bit in the center of the stub end as I drilled a hole large enough to force a small jewelers screwdriver into (I didn't have a small enough "easy-out"). Using a pair of vice grips, I was able to unscrew the stub, and amazingly was left with clean threads to put a new spool pin into as soon as it arrives in the mail.
Some days I'm just not as smart as my grandkids think I am.