VTG Baltimore City Crime Lab Call Box Key & FBI Firearms Identification Booklet. Original FBI booklet, 31 pages, stamped Crime Laboratory Police Department Baltimore Maryland in 3 places. Age is a guess but the last court case we see referenced is dated 1933. Call box key is an early one, had a number but that was stamped over with LAB, has the usual PD stamp also, never seen another one stamped LAB. Check all the pictures, local pickup available.