If you look close, the foam material's "peak" is hiding the rest of the lug, which is resting in one of the foam's "valleys"
Jeepers, you guys are like Robocop with the x-ray vision
I can't tell at all. Stinks getting old.
If it's a full lug, then it's definitely a 686. If it's not, it's a 66.
(Interestingly, some of the late 66's had the two-piece barrel setup as well, making them pre-620's, I suppose.)