I have a good straight aluminium 2-series front bumper, which I am
considering fitting to my '80 model as the existing one is slightly
damaged at one end.

The problem is that the good bumper has a pair of holes in the top
where someone presumably mounted a pair of extra lights.  I don't
want the holes in the top, and am wondering if there is actually a
top and bottom on the aluminium bumpers, or can I flip it up the
other way?  It'll be getting painted black before it goes on, so
existing scratches, etc. won't matter...

Obviously, whichever way up I fit it, I'll have to drill the set of
holes for the '80 front spoiler...