Does it look like the one in the attached link..? If not the a photo of the back would help.
http://www.pmwf.com/Watches/ARTICLE...7th2002WithRob/Opening Tricky Watch Cases.htm
rgds/Anil
http://www.pmwf.com/Watches/ARTICLE...7th2002WithRob/Opening Tricky Watch Cases.htm
rgds/Anil