I'm glad I took accounting classes taught almost entirely via double-entry accounting on ledger paper. Surely there will still be (physical!) beans that need counting and accounting for in the next age.
If not that, I was pretty handy at one point at mechanical drafting with pencil and paper, though I would miss the glorified eraser that is a CAD workstation.
I even know a little metal working (milling, lathing, casting, that sort of thing) and could assist in the construction of such things as farm implements and replacement parts for "obsolete" or outlawed mechanical devices.
I'm also told I play decent (bass) guitar, and so could accompany any of you attempting to pass on knowledge and/or traditions via what would be one of the few surviving methods.
Of course I might be asked to participate in accounting irregularities, or be accused of improperly violating a patent on a device or a copyrighted work, regardless of the involvement of a digital device in the process. *sigh*