I don't like the limp preflop, I think you should be raising this UTG to $1.50
Flop comes, we hit the nuts and we're 4 handed being second to act.
I would lead out here since CO is in the hand and we're 200 bets deep against him.
Half pot looks good. This allows us to get off the hand if a scary card hits the turn (half the cards in the deck are scary) but builds the pot up a little, plus we're not forcing out anyone who has a worse hand like 76xx or T9xx.
If someone raises full pot we can consider throwing it away, but only if that person is particarily nitty since we're so deep.