Does a gap show at the other side of the brass? I'd fill the back with JB Weld but the other side should have no gap
Is the brass pinned through the ricasso as well? If not that needs to happen before you glue it up
The back of the ricasso shouldn't have shoulders that extend behind the brass if you can help it as its easier to fit the handle block up to the brass guard
There also doesn't appear to be a hole in the tang for a pin
You shouldn't rely just on glue to hold the handle on. A mechanical connection in the form of a pin is best in addition to waterproof epoxy