Now ive tried but I cannot find any more files to this I got the arms but that's it. and the only other suits I found was the Advanced suit that had no arms and the chest is a mess and the full Security suit.
Well, the grey pieces are foam and the templates I got were from a ripped model of Isaac wearing the suit. I cropped out each part on the model, cleaned them up, and printed out templates using Pepakura. Traced on the foam with the templates, cut them out, and pieced them together. So these pieces are based exactly off of the in game model.