Paterson Large Plain Contact Printer

Have acquired this printer on eBay. There is a little black plastic "thingy" near the hinge on the base and beside the glass plate. If you have this printer do you know what this thingy is for ?

Thanks from Kanata Ontario

It's used to hold the glass cover up when you are loading it. Semi-useful..

Thanks for the speedy response

My "thingy" still wouldn't budge!
In the end I applied as much torque as my arthritic wrist would permit
The little lever broke rather than surrender to my will!
As my old dad would say "worse things happen in war"
Its a great proofer and hopefully we will have a long and productive relationship.

Emerson in Kanata