New Mystery Object - Jobbing Only

[Dave Hughes]

A museum in Edinburgh, here in the UK is keen to find out what this object was used for - anyone got any ideas?



Something that comes to my mind is a device for holding the type up whilst taking a "galley proof."

Anyone else?

[parallel_imp]

What is shown could be a galley lock, but is it close to galley width? Dimensions would be helpful.
It is somewhat similar to a device I have for holding slugs in a chase for short run imprints, such as diplomas or certificates. Mine is made of aluminum, measures 30 picas wide, about 15.5 extended, 10.5 compressed, with a center retaining bolt as well as two springs/posts.