A classic version control question. After you version-control the components, how do you create/manage a unified version for the whole product? The software world has tried a number of different models. Some work well, some are clunky, and some seem slick but are fraught with problems, often because the descriptions contradict the user's mental model.
Anyhow, there is a fair amount of prior art, in the working model, in the interface functions, and in the back end. The back end part is probably less useful because many systems store changes as deltas. That presumes certain ratios of storage and storage access to computation power. Unless you are running a truly massive--and effective--RAID system, the cost of storage access--disk transactions and head movement--has gone up relative to the cost of storage and computation.
If you're going to work on it at some point I encourage you to open the dicussion to users and to emphasise walking through scenarios to see whether it works as expected--and provides the benefits expected to the user.
If you're going to take this version control step, you might deepen the hierarchy to multi-volume works and multi-section multi-volume works. The step from three to four is usually easier than from three to four, and that is much easier than the step from two to three.