Hmm...began attempting to troubleshoot the short and it's now gone. Pulled all GI to the playfield and turned it on and my in-line circuit breaker didn't blow. I then took my new LED bulbs and put 1 in the socket and turned the machine on to verify between each bulb until I was done and they were all in and I had no shorts.
So, it's probably one of these 4 things.
1. I re-pinned the yellow male pin that led to the playfield GI.
2. I loosed up some of the playfield harness which may have wiggled free a shorted cable
3. A shorted bulb (which is odd because it had been working with the old bulbs prior).
4. The GI braid was touching something that it no longer is.
Either way I'm not going to look a gift horse in the mouth. First things first I'm going to staple down this GI braid while I turn on the machine between each staple to ensure I haven't caused an issue.
Then, I guess it's time to tighten the harness back up and see if there's a scorched or raw wire somewhere. Then if everything's good, hopefully I can get on with the rest of this swap!