The letter would be for you, not to get a reaction/response from W. If you think it would help you to write one to find closure, or whatever - do it. If it is an attempt to stir some feelings in W - it is pursuing and will likely have no effect or even pus her away. Having feelings for her is normal and nobody would criticize you for still having feelings for your W. But what is your goal? That should guide your actions. Not how you think W will react.
Me45 W35 M6 T8 D16 SD11 D0 Dec 07: Bomb July 08: Busted! Thread