After 18 months - H is finally filing.

[MrBond]

IMHO you should respond like this...

I will pass this along to my L and will have him get back to you.

Short and keep him guessing. He's just trying to make it easy on himself. Do whatever you can to protect yourself. If there is anything that you did not discuss, like the 90% custody agreement, then call him on it. Document all of this.