Jeff:
He looks big enough for fuzzies to me.
Or double pinks, if you'd rather.
I feed my babies hoppers:
(She is sitting on her hide in her shoebox (6 quart) home, for size reference.)
Of course, WEIGHT matters a lot more than SIZE, so I would recommend getting a scale for 5 bucks and weighing your little guy.
I have never been that exact about following the Munson plan (or any plan), though. When I am ready to order new mice, I look at the babies and see if they have grown enough to bump up a size by eyeballing their food. (If their current food item is smaller around than they are, then they can move up). I never buy more than a couple months' worth of mice.
I have always offered food to my young snakes regardless of whether they are "in blue" or not. I have never had a baby refuse food due to a shed.
Adults are pickier and I've learned which ones won't eat when in a shed cycle. For instance, Adya NEVER refused a single meal until she reached the 250 gram size, now she refuses when she is blue.
I have heard that to prevent regurges, you shouldn't offer a snake a mouse when they are in blue. I heard that AFTER raising 5 babies, though, without ever having a regurge.