Many US bases have impressive gate guard parks, many of those are high quality and not inferior for official air force museums! Most probably, this B-47B is wearing false serial 20271 and is believed to be 51-2315. The latter was in a major accident prior to 1968. 52-0271 was indeed at Bunker Hill AFB (later Grissom AFB), and maybe this plane is actually the real 52-0271? The plane currently bears the markings 12135 and a sign says that the plane broke its back on a hard landing at Bunker Hill AFB, which forced its retirement, so it may well be the real 51-2315.