Jerry and SG

[Django]

I agree with tigerstrat, Jerry had the Les Paul with the SG shape. I think those were only '61s but I could be wrong. I have a '59 Les Paul special which is kinda like an SG, Dbl Cut slab mahogony body and two pickups, I think the necks similar as well - on mine anyway because the neck is a replacement.
SGs are the first guitar I took notice of, I saw pictures of Jerry and Zappa as well as Santana, Allman, Alice Cooper's guitarist, Clapton, Harrison, Robbie Krieger, Townsend; on album covers, at Woodstock, in the 'Live at Leeds' package etc. It was definately 'the' guitar at the time.

[Henry]

The story went like this: In 1960 the demand for Les Pauls kept getting lower, so the Gibson company decided to give the range a complete facelift, the result was the SG shape. The first ones built in 1961 carried the Les Paul logo (hence the term "SG/Les Paul), but then Les Paul declared he didn't like the new design and asked for his name to be removed. The guitars remained basically the same until 1965.
I think before that they applied the term "SG" (which, by the way, just stands for "solid guitar" also to a few double cutaway Les Pauls in about 1959, but I'll have to check again on that.