It seems like finding this version took at least half a miracle, so I feel like the potential and probably not too effortful reorganization of the repo to accommodate another is a problem worth leaving to be solved only once it's known to be worth taking the trouble.
For that matter, given manual reconciliation of two versions of very old, not previously version-controlled code would almost certainly be required anyway, the additional friction imposed by this repo structure very likely is net neutral in any case.
It seems like finding this version took at least half a miracle, so I feel like the potential and probably not too effortful reorganization of the repo to accommodate another is a problem worth leaving to be solved only once it's known to be worth taking the trouble.
For that matter, given manual reconciliation of two versions of very old, not previously version-controlled code would almost certainly be required anyway, the additional friction imposed by this repo structure very likely is net neutral in any case.