Unopened box and pack grading

[Bkrum]

After a very very lengthy exit from the hobby I have reawoken and trying to understand the modern realities of grading. One item I dug out were some unopened boxes from the 70s and early 80s from all sports (baseball, football, basketball, hockey) primarily Topps and OPC. While I am not interesting in selling them anytime soon it is worth getting them authenticated? I have seen some references to Baseball Card Exchange authentication services for unopened boxes but not sure if that is worth it. Are there some items worth getting authenticated and others that are not? Also we have some packs that were authenticated using the original Global Authentication INC (GAI) service. I understand they went out of business in 2009 but are these still considered legit. In other words if we did try to sell them would buyers be comfortable. Thanks in advance any insight.....