The Velcro has come away from the flap (glue failure), on both flaps.
Tried using this water based (nonflammable) contact cement.
It doesn't work!
Will have to try and get some normal contact cement...
Got the right glue (non water based).
It's the right stuff.
Smells right and has the right sticky consistency.
Applied and let it dry for about 20 minutes.
Once it's ready, you get just one chance so the parts have to be aligned correctly when bringing them together.
Worked out good.
Will let it cure/set for a day or two.
Fixed.