Does anyone know where I can buy casein glue, hide glue, or some
other *natural*, (i.e., animal or vegetable) water-resistant glue for
hardwood? (I only need a small amount!)

Or perhaps someone can tell me some brand/product names that I can
look for in my local B&Q/Jewsons, etc?

In my youth, there was a well-known brand of casein glue called
cascamite, but it looks like the modern offerings under that brand
name are now synthetic.

Thank you,

JD