As you noticed when you had the two components seperated, they are each sealed. If the "gap" bothers you, a dib of silver colored RTV would fill it in nicely and be easily removed if you opt to return function.
I'm just wondering if Honda has made any improvements/changes in the anti dive system to prevent all the problems that occured in the earlier Gl1800's?. Are folks with '06-'09 Wings still disabling the AD?
Just my 2 cents worth but I went the honda dealer and bought a new one for $37. I then cleaned and lubed the old one so I have a spare, although once I saw how easy it is to disassemble and clean I don't know that I'd spend the $37 again.