Hi there,
Had the same issue a few years ago.
As soldering is quite difficult on what seems to be chromed brass parts, I tried several types of glue - all to no effect.
I eventually fixed the loose bars by drilling small holes into bars and base plate (Oh you have to be confident !) and joining them to the base using aluminum rivets.
Since the fixed area is covered by the cowl , you can's see anything from the exterior. Peace of mind.
Cheers
Mich
