From my catalog collection they are all 7 shot L frames rated at .357, (though why anyone would shoot a magnum through such a short barrel is beyond me but that is another topic)

SC Mountainlite - ???
PD - Scandium alloy frame, titanium cylinder, adjustable sights, 17.5 oz
Sc/S - Sc alloy frame, stainless steel cylinder, hogue grips, adjustable sights, 21.1 oz
PD - C&S rear sight, XS front night site, synthetic grip with covered backstrap, 24.5 oz

I'm on a long term hunt for either the Sc/S or PD. If I found the Sc/S I would put the C&S rear sight on it and if I found a PD I would swap out the grips for the Hogue's.

__________________
63, 640, 65LS, 66, 1894C