I just had to leap in here, having retrained to be a Woodwork/Metalwork/TD teacher after injury on duty ended my Police career in the early seventees. In the end spent 38 happy years teaching CDT up to 'A' Level and head of Technology Department. Finally specialising in teaching very difficult children...'Life Skills'
Practical subjects, including CDT, Music, Drama, Needlework, Cookery (Home Ec)and so on have been given the chop many times as Governments and Head teachers try to make a name for themselves and save a few bob. The fact is, not every child can be a Doctor, Dentist, Architect, Politician etc and while they still try to concentrate on these subjects they keep coming back to the fact that nearly everything we humans in the world need to live and use and cook and build a house with ,have been designed, made and tested by a practical, skilled and inventive person... Usually those people have been initially taught by a woodwork or technical teacher, or is just naturally brilliant, like a lot of good model makers.
Coming back to the glues, Cascamite is and was a white powdered resin glue formulated for wood that needed to withstand being soaked most of the time. AeroLite was a two part resin glue used on later aircraft like the Hurricane and the Mosquito. Animal (or Hoof) is the broken down bones, hair etc, usually from Cows leftovers and is heated to make it soft. It is one of the oldest glues in our arsenal and, as was said, is still the very best for musical instruments, because it dries very hard as it cools but becomes quite brittle, which is good if you are a violin and need to resonate. It is not waterproof although similar versions, more refined like Pearl Glue came along in the early 1900s and was used for aircraft too. A white glue, not unlike PVA in consistency was also around being what they called Casein glue.(Made from Fish and Milk!)
The old yacht, if it is the age we think would more than likely be Aerolite or one of the very early two parters, a bit like epoxy. Remember that the early petroleum adhesives like Bostik and the like go way back as well. This was very good for Bread and Butter construction and was cheap enough for hobby-ists to buy. Products made from Tar, Pitch and Bitumen were also around (Look at an old ships caulking)
With this old hull I would do as little damage to the hull as possible. Clean away the paint and fill any cracks or splits. The old glue can stay where it is if it is sound as recoating the hull with newer finishes will give it back its waterproofing anyway. If it is hollow it may be possible to make an access hatch in the deck to seal the inside with some form of resin SP113, Z-Poxy, GRP or similar if you feel the need to stabilise the insides.
Clearly it was built as a 'Set the rudder and go' pond yacht and if you are a perfectionist and want it like it used to be, stick with that, but if you can get inside there is room for modern R/C and a few upgrades but keep the style and the Oldy-Worldy' look and value the same.
Could be a nice project.
Lesson Over boys, tuck shops open!!!..........Ron.