Hi,
I really think you need to give him a longer catnap - APOP if necessary for at least half an hour. If he is only sleeping for an hour at lunchtime, 1.30-7pm is a very long A time, even with a 15 min nap. My lo would not be able to do that and he is 8.5 months now. Keep trying to extend the second nap but I know this is easier said than done.
If you cannot extend the catnap bring bedtime forward to 6.15/6.30pm and see if that helps. I do know from experience about this as my LO was a shocking lunchtime sleeper and I had to make sure he napped later in the day in order to prevent OT. Although the guidelines are to stop the catnap at around 6-8 months some still need it i.e. us!
Personally I would not shorten any naps at the moment and let him sleep up to 2 hours for both naps.
I would also shorten the first A time by 15 mins and see if that produces a better nap. Once he is not so OT you can work again on your routine but until then it is best to just offer LO opportunities to sleep as and when he needs it.
I know it is so tough, we have been there many a time.
Let us know how you get on.
bx