John Rowland wrote:

With the present platform layout, it would have to have been a
bay platform, but one which would have received trains from the Sutton
direction, which seems unlikely.

Does it? There were semifast trains from Guildford which terminated at
West Croydon until a few years ago.

Yes but they never used platform 2. I'm not sure if it would have been long
enough - it's definitely too short for eight cars and may not even take
four. Instead they terminated and then set off in the other direction from
platform 3. I remember one hilarious Bank Holiday when South West Trains
(this was their only service on the line after Epsom) decided it was a
Saturday whilst Connex (or whatever, they ran all the other trains) decided
it was a Sunday. Cue chaos at West Croydon because the platform was blocked!