ABOUT 2 HRS AFTER DEPARTURE, AT 13,000 FT, THE RIGHT ENG FUEL FLOW WENT TO ZERO. THE ENG CONTINUED TO OPERATE INDICATING24 INCHES OF MANIFOLD PRESSURE. ALL OTHER INSTRUMENTS WERE NORMAL BUT WHAT LOOKED LIKE A BROWN STAIN DEVELOPED ON TOP OF THE RIGHT WING ALONG THE SPAR CAP NEAR THE TIP TANK. ARTCC WAS ADVISED THAT A PRECAUTIONARY LANDING WOULD BE MADE AT RATON AND A RAPID DESCENT WAS BEGUN. ON FINAL THE RIGHT ENG NACELLE AND WING LOCKER TURNED BROWN. AS THE ACFT LANDED FLAMES APPEARED ON THE RIGHT SIDE OF THE FUSELAGE AND SMOKE ENTERED THE CABIN. BOTH ENGS WERE SECURED AND BRAKES APPLIED. THE BRAKES WERE INOPERATIVE THEREFORE, THE PLT STEERED THE ACFT OFF THE RWY INTO A SNOW BANK COLLAPSING THE NOSE GEAR. WITHIN 15 MINS MOST OF THE WRECKAGE WAS CONSUMED BY THE FIRE. IGNITION SOURCE AND FIRE ORIGINATION POINT WERE NOT DETERMINED.