Hiya, just letting you know what's been working for us (I know Scotty's younger, though, so you'll have to see if it would work for you)
He has completely dropped his 'formal' nap, but, like Scotty, come 4pm, the grump monsters come out. So, I explained to him that busy people need to rest, so, at around 12.30-1pm, he snuggles up on the sofa, has a drink of milk and his favourite DVD. This is his quiet time (calls it 'avin a rest), and lasts about an hour. Very occasionally, if he's had a bad night or a particularly busy morning, he will drop off to sleep, and I'll leave him for that hour as I suppose he must need it.
Normally though, that rest on the sofa is enough to carry him through to bedtime, recharge the old batteries
