Wow, must have been good scores, either way.
As for stress, beats me... I hit 5 strikes to open a game about two months ago and on that six frame I was dripping sweat and shaking like a paint mixer.
However, a few weeks ago I was hitting all my marks, getting strikes, closing every frame and again I started getting very nervous, I was working on my best score yet.
So about the 5th frame I decided, no more scoreboard watching.
I took a few deep breaths took one last look at the monitor and that was that, I didnt look back until the last pin was knocked down.
It helped, while I didnt get even close to a perfect game I did get my best score ever, funny thing was my wife had to tell my the game was over, since I stopped looking at the board I lost count.
It really helped and next time I start getting shaky, I plan to do the same thing.
This of course probably wont help with a perfect game much as you obviously know you've been bowling strikes.
But, still... either way, good luck with it, it'll come to you soon enough.