Unless its changed since I retired your weapons qualification can be added to your marksmanship badge as a hanger at whatever level you qualified at (Marksman, Sharpshooter, or expert) was that way for all of the 26 years I was on active duty. THe qualifications must be renewed annually.
THere's alos an expret driver's badge and hangers gor whheled and tracked vehicles as well as mechanic can be added. THat badge is pretty much permanent.
Problem is that many units don't bother to cut orders for anything but expert with weapons. The Drivers badge requires orders as well.
You are correct about the qualifications, annual quals have to be maintained. I have the drivers badge (wheeled), in addition to expert on rifle and pistol. These have been renewed annually, and if the unit qualifies on a certified range, and it is recorded, it goes in the 201 file.
... and sadly, yes it does depend on how thurough your unit is with its paperwork. (as always)