Well depending on how the law is worded, some people have gotten away with chest reconstruction and/or histo even if the law says "sex reassignment". Since in most cases the law isn't defining this, the letter can say something to the effect that "________________ has completed all steps necessary for gender reassignment." Or that "______________ has completed irreversible surgery needed to complete gender reassignment" or some combination. No one lies and no one gets hurt.
I can't guarantee that this works, as I am assuming it goes down to who handles the paper work.
--Jay J