William Duffield
Urea-formaldehyde was my first guess when I spotted it. (I've run into it in another restoration job.) Great for laminations and veneer, because it doesn't creep, but not so great for chair joints, which must remain flexible. There's a dollop dripped on a leg stretcher, and it is very hard, more so than the yeller glue and epoxies that I have used, but not nearly as brittle as old hide glue.