To all, thank you for the advice. As I said, I went with Speer, cross-referencing other data, but ultimately went with the bullet manufacturer's numbers. I kept reading/hearing "get the manual - read it - follow it". I didn't hear "get 4 manuals, question the numbers from the manufacturer, etc...". No disputing that that was the wrong call here, and fortunately my gun (and I) lived to tell the tale. I reckon I should open some sort of correspondence with them (Speer) to find out why the extra grain(+) starting load. Maybe it's tribal knowledge to just not use their data among the more experienced, but I think it's confusing for new loaders who are trying to 'follow the manual'.
As to my current situation... I haven't had a chance to get back to the range since (or check the brass - still keeping it separate). I did get a few minutes last night though to pull my unfired Speer loads of 180gr's that were the old/high values. I only had 10 rounds. I checked Accurate's postings and cross-referenced with Hornady's (180gr FMJ-FP) this time. I filled 5 with 5.9gr AA5 and another 5 of my Speer TMJ 180gr with the same 5.9gr - all Blazer brass and all at 1.125-1.126 OAL. I might try several at 6 and 6.1 and see how they compare after firing the 5.9's. I also intend to put some Gold Dots (180gr) to the same 5.9, 6 and 6.1 to compare. Got some labels and several boxes to keep things all separated.
Again, thank you to all who've helped out here.