And a GREAT story- lots of fun details, a very sexy situation and a very hot wife! Wouldn't it be wonderful if her fantasy could come true- maybe you should think of it as a long term project.
Can we assume they live too far away for him to stop by for an afternoon some time? Can you visit him when she's away? I would think with an overnight stay at either end, there could be an opportunity for your wife to be seen dressed "casually" by him, and judge his reaction. We all know he's not forgotten a moment of that summer!
Thank you for the hot story, and all the images in my head right now