THE PLT TOOK OFF FM THE MARLBORO ARPT & FLEW TO 2 OTHER ARPTS BEFORE LNDG AT THE MILLER ARPT AT BURGETTSTOWN, PA, WHERE THE ENG WAS SHUT DOWN. HE HAD DIFFICULTY IN STARTING THE ENG & REMAINED ON THE GND ABOUT 1 HR. THE PLT TOLD AN AVIATION SAFETY INSPECTOR THAT HE & THE PASSENGER HAD CONSUMED ALCOHOLIC BEVERAGE WHILE EXPERIENCING DIFFICULTY IN STARTING THE ENG. WHILE CRUISING ON THE NEXT FLT, THE FUEL SELECTOR WAS SWITCHED TO THE RGT TANK. APRX 20 MIN LATER, WHILE ON AN APCH TO LAND AT OLD BRIDGE, NJ, THE ENG LOST POWER. DRG AN EMERG LNDG, THE ACFT COLLIDED WITH TREES ABOUT 25 FT AGL, FELL INTO A SMALL CREEK & CAME TO REST AGAINST A LARGE TREE. NO PREIMPACT PART FAILURE OR MALFUNCTION WAS FND. OPENED BOTTLES OF BRANDY, VODKA & ORANGE JUICE WERE FND IN THE ACFT. THE LEFT FUEL TANK HAD BEEN 'TOPPED OFF' AT THE MARLBORO ARPT, BUT THE RGT FUEL TANK HAD NOT BEEN REFUELED FOR ABOUT A MONTH. PLT'S LOGBOOK WAS NOT RECOVERED. ON AN APPLICATION FOR HIS LAST MED CERT, DATED 2/21/84, HE STATED HE HAD 700 HRS TOTAL FLT TIME.