I'm definitely not qualified to help you, as i have almost no idea what either bit looks like, but is there a way you could make clips to secure your high beam to the grille? something that would push onto the horizontal or vertical parts of the grille and hold on tight, like plastic C shaped things with a flat back... like |C
b o|
e |C o| <-- grille showing vertical tubing parts
a |C o|
m o|
I'll be quiet now...
edit: the spaces didnt keep, cant use html but hope my words gave you a useful idea of what i mean.. could draw it if you want...