Ruska 1461-801 screw snapped

[USMCPMEL]

Anyone know where to get a replacement? Also does anyone know how to take this thing apart? I can not find a manual so far and don't want to just tear into it.  I was using the Ruska to apply pressure and for some reason it just snapped. Low pressure I had just started to apply pressure. I have been using this thing for years and have never had a problem. I guess it was just old?