@D500 posted:Walthers "Goo" (not "Goop" - different glue).
Goo, I do believe, is permanent over geologic time. It's even ugly, as a truly good glue should be.
😁😁😁 Back when I was major "HO-ing", I found that Goo is "permanent"... until you needed to separate the pieces. It can be cut loose, and since it doesn't really penetrate, it (usually) won't scar the pieces. I once picked up some beautiful old Walthers passenger cars; some needed a few minor repairs, calling for the removal of some sides. A little careful knife work and patience and they were loosened and cut free. Interesting stuff...and still available, I think.
Mark in Oregon