Just now there is an old Desmond woodworking vice for a very reasonable price on Raleigh CL 'Tools for Sale'. This vice would be well worth restoring to a trophy condition.
Good luck.
It's a quick release vise.... That's why the threads are cut like that.
Let's see a pic of the bottom. It looks like it's the brass "half-nut" design. I have two like that. I would check the condition of the nut and make sure the spring and pin are in place.