Had some trouble finding it here too. Called several oil retailers and got the big "no". Even my AAP store said they couldn't get it.
Having been a sales rep with Napa I felt if I gave them the Valvoline part #, which is 066, they could locate it. Once they had the part # their system brought it in.
I bought a case of 6, which should last me 2-3 years for what I have planned.
If it comes down to it I'll simply use a CF oil, or some diesel rated oil, where I plan on using this additive. Probably would make more sense but for now this is easier for me.
FWIW I like the moly VSOT contains.