I just acquired a 60's round badge snare which is a model 4157, 8-lug. I also have a 4105 (dixieland) 6 lug. Serial numbers are less than 100 apart. They are both 6-ply, however, the 4157 model has thicker plys in it than the 4105. It definitely appears the 4157 model was re-wrapped... but the shell does have the gold sticker with model and serial number, silver sealer, typical looking gretsch shell..... but the shells are different thickness when comparing the 2 models, that supposedly were made around the same time. Anyone know anything about different thicknesses in the 6-ply shells????