As promised here is the information regarding the RADAR national key scheme for toilets that use the key i.e The Paisley Centre..
the web address is www.radar.org.uk
The National Key Scheme (NKS) offers independent access to disabled people to around 7,000 locked public toilets aronud the country. RADAR would like all providers of accessible toilets to keep their toilets unlocked if at all possible. The NKS is suggested for use only if the provider concerned has to keep the toilets locked to stop vandalism and misuse.
Also more information on services can be found at www.accesspaisley.org.uk