This was my solution:
10 x 100 free @ 1:30 (aerobic pace)
8 x 50 kick @ 1:05
6 x 100 pull @ 1:30 (85%)
50 easy drill
4 x 50 fly @ 1:30 (hard)
150 cool down
The 10 x 100 was fine but got kind of long towards the end. But then I felt really good pulling.
Went :32 on first 50 fly, and that was glorious. Took it out fast and loose and then dropped the hammer on the way back. After that I was gassed. I finished as hard as I could, but it was a rough set.