Sax.45,
The 1977 Sec Six box, red & black or yellow & black? I'm thinking it's red & black. If so, I have GA-34HT Big Grip box with a 1979 dated manual. Will this work?
lmd
PS. If anyone else is looking for Security Six boxes, PM me with your needs. I have three red & black boxes, six yellow & black boxes, plus three more yellow & black boxes with shipping sleeves.