Good afternoon, I was searching for info on what I believe to be a 1974 Gibson SG. I was trying to identify further from the truss rod cover and read some of your previous posts. The cover is the “S-G” variety. Do you know what years those were produced and what models they put them on? Here is a link to the guitar, I bought it yesterday. https://corpuschristi.craigslist.org/msg/d/vintage-gibson-sg/6712007428.html