NEW DECOR ON WHEELS rolls into place as the Westner’s new diner arrives at its Post Road home. The old diner it re places can be seen at the rear, as it awaits the truck that will haul it away as a trade-in on the new unit. The sleek new 60- seat diner was towed up from New York Monday night, and arrived yesterday morning. (New York allows roads like this to move only at night — Connecticut lets them use the roads only during the day.) This marks the latest phase in Lennie Cocco’s development of his property, which has seen the addi tion of the “Playgoer Room,” a new chef, and a Maitre d’Hotel in the past two years, (Photo by Dick Hazelton)