I've been really interested in SJ history lately so I just took a look at the old catalogs. Here is what I see:
'64 - Shows top vent with metal handle over it and peg legs.
'66 - Lists "improved damper control" and picture shows wooden handle facing away from vent. Image shows peg legs. Only color listed is Jet Black.
'68 - Same handle/legs as '66, no color listed. Image may be speckled, but it's hard to tell.
'71 - Same handle/legs as '66 & '68, kettle appears speckled.
'72 - Shows speckled, red and green finishes. Legs changed to connected tri-wire leg set.
So my refined guess is it somewhere in the '68-'71 timeframe. Thoughts
@Winz ?