Brilliant stuff as usual just loving the old signage too. I'm only sorry i live on the opposite side of the country still thanks for bringing it to us in the form of excellent reports.
I'm not convinced you would need planning permission as it is owned by Peel Ports and they could easily knock down this building as part of their development of the port. Here is their link with several bullet points to expand if you haven't already done so. https://www.peelports.com/port-locations/liverpool
Peel don't have immunity from planning regulations.
Not that I care if they have permission or not, but planning documents sometimes contain useful information e.g. heritage assessments etc.