I think your letter sounds great. It's to the point without assigning or accepting undo blame. Good job!

I think tuning them up is still a valid concept.

We're still waiting for the Municipality to come collapsing down- where's the update, dangit!

cover all of your bases...that's what I always say! seriously though, I've had to deal with my daughters father and though he never deserved it I always let him know where we are and how to reach the girls, he doesn't...ever...but they'll grow up knowing he could have and that my dear is selfishly for my own satisfaction.(and so they'll know he's a dirtbag..but mostly for me)