I was always impressed with the LTU TriStars, mostly seeing them lined up at Düsseldorf or Palma de Mallorca, looking good in their livery and impressed with their size in comparison to most of the other IT charter aircraft of the time. A very well run airline back in the day, but then again every German airline was in tip top form at the time. Perhaps the OP should consider asking these questions on airliners.net, as there always seemed to be a very large airline worker contingent posting there in the past. Perhaps that has changed in the meantime.
I remember going into the belly lounge of the PSA TriStar at Farnborough in 1974, the lurid, yet pleasing colours of the aircraft's interior made it seem so exciting in comparison with most European airlines at that time. Perhaps only Braniff could best them in the colour wars ;-)