I am a master sprinter, born 1970 and would appreciate some feedback:
Here are 3 vidoes. Sorry, the 3rd one is turned upside down and I cant get it rotated.
1. June 2012. My first 100m ever after 9 months of athletics training (started in September 2011)
12.48 (-0.7 wind)
This is even the personal best time as it was against headwind of -0.7. At that time, my technique was not very good I guess, but I am sure you have a p.o.v. there. That said, it was probably my best start and reaction time ever (the winner was not much faster in the first 5-10m and he runs 10.79).
At that time, I weighted 72.8 kg and had stronger legs than now.
2. October 2012. My 4th 100m race. This time it was after a 4×100 relay 1.5 hours before and I had a hamstring injury.
3. June 2013. My 5th 100m race. This was the final after running 100m at 12.54 1.5h before which was not a great run. This one was a bit better.
As that time, I weighted 70.6 kg (vs 72.8 kg) and felt some lacking power, especially at the start and drive phase.
Unfortunately video quality is not that great.
And finally, some actually measured and assumed split times per 10m.
As you indicated, my potential current best 60m time is probably closer to 7.8
10m split cumulative
1.140 7.67 + reaction time would result into: 7.835 s
reaction assumed 0.165