Socket outlets 3 phase - ELU

[GCE]

Hi
Be interested to hear what you guys think

We have a case at a fast food franchise that is wanting a COC – We are not 100% sure on the build date but think it was around 2006
On inspection we found that no 3 phase kitchen socket outlets have ELU protection

If we look at the installation as a whole there have been revamps done to general electrical in lights , front of house single phase sockets and possible extra single phase sockets and light circuits , signage added
We cannot be 100% sure if there has been work done on the “old” 3 phase socket circuits as in extended or moved 3 phase socket or an extra 3 phase socket added (photos attached )

How do we treat the installation with regards to the missing ELU protection
Do we say it was done prior and complies or would it need to be brought up to present day standards ?