Ok, I got it - regarding the tail and 1950s Les Pauls versus reissues:
from here:
Gibson Les Paul Sunburst Standard guitar info 1958 1959 1960 sun burst vintage value "Since the late 1970s, Gibson has made many reissue Les Paul Standards which look very much like the original 1958, 1959, 1960 Les Paul Standard model. So how do you tell the difference? One easy way is by the positioning of the stop tailpiece. Gibson has never gotten this right on any of their reissue Les Pauls. On a 1956 to 1960 Les Paul with a stop tailpiece, if you run an imaginary line from the center of the Low-E tailpiece stud through the center of the High-E tailpiece stud and continue that line, the line will touch the north edge of the Neck volume knob and the south edge of the Bridge volume knob. On reissues the line through the center of the tailpiece studs runs right into the Neck volume knob (the line is no where near the Bridge volume knob)."