B190 Enthusiasts

1997 B190 used a hose to find leak on inside top of couch window. Water got in at seal of fiberglass cap to van body. There was what looked like "plumber's putty" all around this joint, left side, right side and rear. They just filled the rain gutter and up the fiberglass a little. I removed all this putty and found water under the putty evverywhere.

Was this the Airstream factory approach to sealing this joint ? Seems to negate the purpose of the rain gutters.

Do the rain gutters only drain when the van is nose down?

Any idea on how I should reseal this joint? Product?

Thanks in advance,
Charlie