Welcome to the forum! You will find a wealth of knowledge here.
When it comes to knowing models and details, it is usually revealed with
photos of the movement, serial number, and the inside of the case back.
However, only a watchmaker (or a confident hobbyist with experience) should
attempt to remove the case back. Occasionally a member will recognize a watch
and provide some information without the benefit of the movement/case back
photos.
I am of absolutely no help here, but I did want to mention one thing: the type
of bracelet that is on the watch in the photo can damage the inside of the
lugs where it is attached. Metal on metal may cause marks or grooves to be
ground into the lug. I suggest removing/having the bracelet removed by someone
qualified to do so. Plus (and this is my opinion) it will look much nicer on a
leather strap!
Stand by for (hopefully) further assistance from members who have far greater
knowledge of vintage IWC than I.