Gabshall

Directing the Mentor cfg to the default fx_navgre fixed the landing light problem and returned the starboard light, but how could I resist the challenge? The Mentor fx_navgre file is simpler than the default and only contains four ParticleAttributes. I modified the ParticleAttributes.2  entry to reflect your alternative texture and it worked! Landing lights no longer disappear at 1000ft agl and the aircraft has starboard nav visible form the vc. So now I have two fixes.
 
Finding the source of the original problem was only possible because the exclusion function on the fixer was such a useful diagnostic tool. The fixer software is an impressive application.
 
Many, many thanks.