So far as I'm aware there have been no cases so far of older trains being retro-fitted - all those without yellow fronts have been built within the past few years.
TPE's 185s have had their lights converted to be compliant with the latest specifications, although they do retain the yellow front for now.
- I like the 'MIDLAND PULLMAN' font and the livery. I was never around when the original Pullman was there.