MY: you just started a new thread with the picture. i'm not sure you can delete the thread so just make a post asking a mod to delete it and post up picture on this thread you started. ok?
there is writing on the side of the vise you posted in your first picture and pretty sure it says Rock Island because Prentiss, Parker, Reed and other vises don't cast their names in vises like that. if your eyes are younger maybe you can see it and make it out. from my blown up picture the vise looks like in pretty good shape and there is a small piece of the back of the swivel jaw missing that shouldn't be a deal breaker.
the # on the bottom and the shape also makes me think Rock Island vise.
good luck