Yeah, it was a while ago though
And I think the main fascination with 170 397 & 398 were (and still is) this:
CT had 170/5s & /6s which are quite early 170s. They then took on two porterbrook spot-hire units, part of a later batch which had the different lights. These two, were then kind of special, as they also had first class seats in the middle coach, which was declassified. This was before CT got exMML 170s which had the same set up in 3 car units. So out of 397 & 398, 397 followed me around, so I chose that one
Of course, there could be other reasons for other
Quite sad isn't it