Although current locos such as the 66, 67 etc. seem 'fairly' modern, can you imagine a time where you will see less of these locos on the mainline and a fair few in preservation? Fair enough, the class 66s and other locos have a long life ahead of them, but there will eventually be a loco that will gradually start to replace locos such as the 66. Also, are there any fairly new(er) locos (20 years and younger) currently in preservation? Please share your thoughts and opinions.