I know it sounded onerous. Explain your boat and your problem. Perhaps only a Catalina owner could understand.
Or perhaps armed with the knowledge that not all Catalina 25's were designed or built the same. The difference as explained by Ward,
" there are many variations to how the fiberglass and wood may be layered. Stringers may be fiberglass and the wood may be sandwiched between two layers of fiberglass."
The Catalina 25 Design
During those 14 years of production, the design went through a complete metamorphosis, starting out as a very simple and inexpensive trailerable swing-keel design, and ending as a relatively sophisticated minicruiser.
If you consider all model years, you can find Catalina 25s with five different keel configurations: cast iron swing-keel, cast iron fixed keel, cast lead wing keel, cast lead fin keel without glass jacket, and in later boats, a lead keel encased in fiberglass. In the later boats there was a choice of fin keel, wing keel, or swing keel, and standard rig or tall rig. However, the swing-keel model, with a board-up draft of 2′ 8″, accounted for well over half of total production.
As the design developed over time, features changed enough so that in a number of respects the early boats are very different than 1987 and later model years. As a consequence, its imperative for prospective buyers to know what model year theyre looking at when shopping for used boats.
The concept of helping an owner of a 40 plus year old boat that has had at least one previous owner over the internet engages the need to more carefully know all you can about anything that may involve cutting. Especially when cutting away the pan (an Inner molded fiberglass structure that provides internal boat structure and form - one of the innovations of Catalina ).
You have listed 30 years of sailing experience so this comes as no surprise... eh.