Free Traffic Legal Advice

So let's get this right.
You had a perfectly good permit valid until the 8th. YOur new permit commencing on the 9th arrived on the 6th , and instead of replacing it in the car when the old one ran out, you put it in the car, and threw the old one away. So do the paper permits have a start date on them ?  Also, I presume this swap-over practice has been going on for a long time, since 2011 ?

So have you submitted representations yet ? If not, I suggest you submit reps based on the fact you have always swapped over the permits as soon as the new one arrives to avoid forgetting about it. Point out you have been a resident since 2011, and have never before received a PCN for swapping the permits immediately.  Post up their inevitable rejection when you get it. I you could post up the actual permit, it would help. Redact the reg number if you want, but it's not important.

The PCN is unlawful because it adds on the unpaid RUC charge. There is no power to do this in Regulation 7 of the RUC regulations.
https://www.legislation.gov.uk/uksi/2013/1783/regulation/7/made
Also stated by Caroline Shepard in an adjudication concerning DART in 2018.

The 56 days only applies to the Traffic Management Act 2004, but not the LLA & TfL Act 2003 under which your PCN was issued.

They haven't re-offered the discount, so it is a no-brainer to take them to London Tribunals as the penalty is the same and there are no additional costs. For delays where no defined in law, the adjudicators normally have 3 months before they will consider a delay in response.

Do I actually have to pay 11 tickets at £65 each ?

Well, yes, is the answer unless you can persuade them to ive way a bit on what is clearly a very harsh penalty.

One aspect which you can follow up, is to compare the dates on each PCN with the date you received the first one that alerted you to the problem. PCNs dated after the first one and which are also dated before the date you received the first one, can be appealed on the basis that you didn't know about the contravention until the first PCN arrived.

Also it will be best to submit a single representation covering the 11 PCNs, with a request for 10 out of the 11  to be cancelled. YOu need to emphasise you have lived on the restricted street for 6 years and hope the council can exercise their discretion for a well-established resident.

Finally wait a bit to see what the others say, but don't miss any deadlines on the PCNs.

Here is the GSV satellite view of the YBJ. 
https://maps.app.goo.gl/qm67F5ALjXQcHTzT7

Although the box is strictly speaking extended beyond the junction, it ends where the curve of the kerbstones ends, so I am not convince at all that this is a strong appeal point. IMHO you are on stronger ground with the argument put forward by Mr Chips, namely the video does not show your point of entry into the box  However, it does show you following the car in front very closely, so it looks as if you took a chance and it didn't pay off.  Sorry to be so negative, but I'm only trying to look with an adjudicators mind at the video, as it is the sole evidence. I think if you won at London Tribunals you'd be lucky, but see what the others say.

This YBJ must be a nice little earner for TfL, because back before your car in the video a black and grey Mini stopped in the same place !

Well, the first of your pictures I open shows a clear yellow line with some leaves, then the third shows the restrictions sign right by where you indicate you were parking, so I think you'll struggle with this. However, one has to wonder why enforcement is now taking place if you've parked there fairly regularly for 2 years.  Maybe you have been lucky, but we do see this sort of thing all the time.

For me, your only real argument against the PCN is your regular parking without penalty.  This is called 'legitimate expectation', but somehow you'd have to show how often you have parked there over the years. Another argument that I don't think is particularly strong is the mess on the carriageway partly obscuring the yellow line, but your own photos shows the line is visible. The whole cul-de-sac has yellow lines, and signs so this is no real guarantee of success.

The PCN looks OK for content, so no mileage there.

Sorry not to be more positive, but I would not risk the discount if it were me. Submit representations but I don't think they'll give way. If you go all the way to adjudication via the Notice to Owner, you will be liable for the full £70 if you lose.

Did you turn right into Chestnut Drive, or turn left ?  GSV is out-of-date for this restriction, being last updated on April 2019. For a left turn into the street, one woould expect an advance warning sign to be present, because if one is not forewarned, it is too late once the turn is commenced. For a right-turn it's not such a problem as the signs can be seen before starting the turn.

So, are there any advance warning signs ?