This is a company car.
This is a factor in how you manage the issue, therefore what's their policy regarding PCNs.
As regards the signs and SYL, they're c**p.
The hours of the SYL are the same as these so-called res parking bays on the footway. Impossible. The legal issue is that the SYL prohibit parking on the carriageway AND FOOTWAY during the CPZ hours, therefore they cannot co-exist. Furthermore, as the res parking signs are NOT of the form which permits parking on the footway then by virtue of these signs the council is ENTICING motorists to break the law. It has a LEGAL DUTY to enforce the law, in this case a statute, and is derelict in this responsibility if it does not i.e. they must penalise everyone who parks wholly within, partly within or not within these markings. So, why single you out?
They're a bloody shambles.
But they're also judges in their own cause and you could submit reps supported by the most eminent jurists of the last century and they'd still say no!
The next stage would be a Notice to Owner served on the registered keeper who might be the company or it might be a leasing company, but it certainly isn't you, I'm afraid.