Hi MntnMan62!As to the curved legs on the tom, they are original Slingerland. The curved legs replaced the straight legs sometime at the end of 1967. Most straight legs, with no knurling, were designed for use with the "push-button" leg mount casings and the older style leg mounts that used a captured-bolt wing nut. The new "curved" legs made use of knurling at the top to allow the large wing bolt to better grip the leg. However, Slingerland, like every other major drum manufacturer, would use up old legs first. My 1967 Slingerland set has a 16x16 floor tom with factory straight legs, but with the new 590 mount that uses a large T screw!-Mark
Mark, Slingerland floor tom legs and mounts per Dr. CJ Wenk:
'58-'65= straight legs with push buttons
'66-early '68= straight legs with 'T' wing screw
early '68-up=angled legs with 'T' wing screw
Your '67 FT is as expected.