EK: that Starrett Athol vise is worth a lot more than $45 if it works, but since the main screw is out it could have a bad vise nut and or a missing sleeve. other than rust i don't see much wrong with it and it looks like maybe a 4.5 or 5 inch wide jaw. pristine it would be worth $300+-
can you see it in person before bidding? look at the vise nut and post pictures and i'll try to help you if i see them. as you might have seen i check GJ threads fairly often especially the vise threads.
cheers