Just to add to your whole post, it’s probably not necessary to add back much in deferred taxes because the holding period is so long, which opens up many opportunities for essentially deferring the taxes indefinitely. Just look at what happened with the Gilette stock purchase. Gillette -> P&G -> Wholly owned Duracell - the capital gains ended up deferred indefinitely (I am not an expert but this might actually lead to a big book-value decrease—gotta ask an accountant). The US tax code is purposefully tilted in favor of those with long holding periods, especially very long ones (though the latter is much less obvious at first).
Another option that could happen under new management, would be directly spinning off the shares. The individual owners would become liable for the capital gains, but at least under current rules, this would be a significant savings. In addition, any individual can still keep holding, and eventually could pass on the stock at a stepped-up basis to their heirs, essentially tax-free (up to the estate exclusion). That’s without even getting into trusts and stuff like that.