You are considered to be the 'owner' for these purposes if you were the registered keeper on the date of the contravention.
Were you?
As an aside, I think these PCNs are worded dreadfully because they'll be some/many recipients who simply want to represent that 'the contravention did not happen' and who beat themselves up about what the hell is a 'prescribed order' and 'scheduled section 36 traffic sign'. Even the front of the PCN only refers to 'contravention'!
Anyway OP, as regards the omission of signs my understanding is:
The Traffic Signs Manual reference is para. 4.2.9 and Fig. 4.12 pages 29 and 30. This still refers to 'should' not 'must'.
The LATOR (
https://www.legislation.gov.uk/uksi/1996/2489/contents/made) reference is Regulation 18, but again this refers to 'may consider requisite ...adequate information'.
Similarly, the Traffic Signs etc. Regs refer to siting 'as near as practicable' to the place where the prohibition has effect. Whether there is case law on this point, I don't know.
But in any event, put together this means that the burden is on TfL to show why, in this case, the only sign has been placed 50m in advance of the point at which the prohibition applies.
As regards 'as near as practical', I could possibly see TfL arguing that the sign is placed at the same point at which footway parking is permitted within a parking place and that in order to avoid obstructing cars parked on the footway the sign has been placed immediately before and that after is not practicable because of the trees.
Who knows what they'll argue, assuming you get more than a simple 'niet' from them!
