Understandable about you guys being busy and yes I'm past my discount period - I think I was still okay yesterday but completely forgot about it.
Advance warning signs from your first link - coming from that side there actually two warning signs prior to the road and the entrance to the road is easily visible.
Although I was coming from the opposite side - where the sign from your second link should be - it is no longer there and there is no other warning signs coming from that side in the whole Burnt Ash Road. Coming from that side the School Street signs are blocked by low trees - see the pictures in my original post.
Apologies for bumping the thread earlier and thank you very much for your advice.
EDIT: Actually according to the letter I've got I should be outside discount period but when going to Lewisham Council website to check their evidence it says I still have time until 31st of October to pay the discounted amount.
Here is the video from Lewisham Council -