Hi
I agree that is it too early to move to the one nap at 9mos. You say he missed a couple of morning naps, how many and what has happened when you tired to get him to sleep?
For version 2 of your schedule:
8am bf
930 breakfast
11 nap of 2 1/2 hours
lunch
try for another nap around 4 but doesn't seem interested
7 / 730 bed.
The 2hrs+ nap in the morning is probably giving him all the sleep he needs for daytime. So i would limit that 1st nap to 1.5hrs and then see if he will go down again for nap 2 about 3 or 3 1/2 hours after nap 1 ends. If he still refuses nap 2, then i would cut nap 1 back to 1.15hr and try again.
It could also be that a developmental issue is on the way, crawling or standing or something of that nature. That can also mess w/ naps. But i would keep trying to get him to take two naps a day. Last point, napping in the push chair might not work any more. I seem to remember my LO found it too distracting to sleep in her stroller about this age, bummer i know!
I hope that helps.