All right Tex, your trying to go from fast to sudden. I'll throw in a few tips but you might already practice them.
1) Your holster times are excellent, you wanna go fast? Do one shot drills more than anything else. RELAX, RELAX, RELAX.
The biggest block to speed is your mind, concious thought is too slow, at the speed you want to achieve. Now here is a tip that will improve your times by 2 hundreths of a second, only for competition, draw at the beginning of the beep, sounds silly, but true. Most people sub conciously draw at the end of the beep. Thats about 2 hundreths. Below 1 second, everything is mental, read " You can't miss " about a hundred times, and any of Brian Enos, or J Michael Plaxco's stuff, I learned alot from an olympic rifle training book that I can't recall now. Lanny Bassham has some excellent books and tapes for mental conditioning. Remember, you have to believe you can do it.!!!!!!! As Bill Jordan once said," your not going to see if I can hit an aspirin from the hip double action, Your gonna tell your friends how I hit an aspirin from the hip double action." Visualization of what you want to accomplish is key. PRACTICE, PRACTICE, PRACTICE, As Uncle Jeff was fond of saying, " your sights are there to verify what your body already knows" That means, if you practice enough, your body has presented the weapon where it belongs through muscle memory, your eyes take that last micro second to verify it.
2) Your low ready times seem a big contrast, maybe you should concentrate on that for one shot drills, I had the same problem when I started shooting the Glock matches where everything is from the low ready, I was just used to drawing and shooting, not raising and shooting, and it felt awkward. Kind of like Butch Cassidy and The Sundance kid, when Robert Redford said, can I move? No just shoot the target, but I need to move. Moving/drawing was his element.
3) Perfect Practice makes perfect performance. One shot drills are not glamorous, but build excellent fundamentals, once you achieve the perfect first shot, the foundation is laid for the rest. Practice on your visualization of accomplishing your goals. Visualize your perfect draw and presentation with no hesitation, and it ends in a perfect trigger press just as the sights align. A good friend once commented on a junior shooter that was completely fast, " man that guys shooting moving targets" meaning his transition from target to target meant he was reverse leading the targets as he swept them. Do not be discouraged, Ed McGivern, Bill Jordan, and now even Jerry Miculek did and are doing their fastest work in thier 50's.