NOTE ABOUT THE A TUBE:
In the past week, I've employed an ABC (or A, B, C) symbolic configuration for three tubes, where C is enclosed within B, and B is enclosed within A. I'd like to highlight a key point regarding the visual representation of "A" in this configuration: it's not necessary for the outer surface of A to be perfectly smooth, as this surface doesn't need to fit inside any other tube. This opens up the possibility of reinforcing A with collars or doublers at critical stress points, such as its two ends and potentially some sections along its 60-inch length.
Further, since As are visuals at tote, some As may be on their exteriors different from other As. The As of the LE can be different from the As for spreaders. Likewise the A on keel may be different from the other As. The As in spreader may be made to be doubly tapered to resist buckling.
So, how about signifying the species: A-lead, A-keel, A-spreader. Those three As might have same ID, but distinguishing exterior builds. Indeed, the stresses on A-leads will be distinguishable from the stresses on A-keel, and A-spreaders. So, these licenses should make for a more interesting solution for a tiny-packed HG.