Thanks for the info about MEK, Equill. For twenty years, it has been difficult to buy as an industrial chemical in the UK -- it was commonly used in the printing industry prior to that time to rejuvenate offset blankets and rollers, and the offset roller application has a clear connection to vintage calculators and printers.

From the Health and Safety notes, I understand that MEK is still available in the UK (and presumably EU) as a *scientific* chemical (and *professional* industrial chemical).

Returning to the original post, what sort of size cracks are you talking about? How big are the "little hinges"? A photo might help. Gluing tiny things to anything rarely works, but there are alternatives.