NMAC BTWN AN SMA SEL DSNDING AND AN SMT TWIN CLBING NEAR A RESTR AIRSPACE.

Narrative

I WAS NBOUND FROM LGB-L71 IN A GRADUAL VFR DSCNT FROM 8500 FT (AT CRUISE); JUST OUTSIDE R-2508. USING VFR FLT FOLLOWING SVCS WITH JOSHUA APCH. I WAS VISUALLY CLRING FOR OTHER ACFT AND SPOTTED THE KING AIR (BLUE STRIPES ON WHITE) AT MY 5 O'CLOCK POS AND SLIGHTLY BELOW ME; AT LESS THAN 200 FT RANGE. I DISCONTINUED MY DSCNT; STARTED A CLB FOR INCREASED SEPARATION; AND A BANK TO MAINTAIN VISUAL. I OBSERVED KING AIR CONTINUE TO CLBOUT AHEAD OF ME WITH AT LEAST 50 KTS OVERTAKE. THEN THE KING AIR TURNED NE INTO R-2515. I HAD NO TA FROM JOSHUA. THEY RPTED NO RADIO CONTACT WITH THE KING AIR. I ADVISED JOSHUA OF MY INTENT TO FILE A NEAR MIDAIR RPT WITH THEM AND CALLED THEM ON PHONE AFTER FLT. MY OBSERVATION OF THE KING AIR'S LACK OF MANEUVERING TO AVOID CONVERGENCE IN CLOSE PROX STRONGLY SUGGESTS HE NEVER SAW ME. IF I HAD NOT BEEN SCANNING AND MANEUVERED; THIS WOULD HAVE DEFINITELY BEEN A MIDAIR! CONTRIBUTING FACTORS: KING AIR LACK OF VIGILANCE; ATC NOT IN RADIO CONTACT WITH KING AIR; NO TA FROM KING AIR; CONVERGING ALTS BY BOTH ACFT.