Strange interchangeability of parts

on our 2 flight to US and back
we had 2 different painted 744
on the Gatwick flight out we had an old non metallic red, but had one engine cowl in red metallic
and on the return to Heathrow we had a full metallic paint 744 but 1 engine cowl was in the old red ?|
we had 2 different painted 744
on the Gatwick flight out we had an old non metallic red, but had one engine cowl in red metallic
and on the return to Heathrow we had a full metallic paint 744 but 1 engine cowl was in the old red ?|