Thanks for your reply. I feel that something similar to what you describe happened to me in my last race (still trying to erase from my mind).
In my 100m race I reverted back to my old stroke with all its inefficiency, which explains my inability to improve my time. In the 200m, however, I tried to use my new stroke, but was unable to get any speed out of it. This was my first time racing 200m, and I was concerned about conserving energy. Proof was that I wasn't as tired finishing the 200 as in the 100.
So what is the answer? How can I develop a fast stroke using the correct TI approach? Converting your times from yards to meters, I see that our times are similar (1:18 for 100m short course), but your goal is more ambitious than mine (1:07 for 100m).
I have counted my strokes per length, and think that this is where I should work first. I watched myself on video, and counted 46 spl for 50 meters in the 100m race, which is very far from the 25-30 spl that I understand good racers accomplish.
All suggestions are welcome.