I've installed Xcode Commandline tools which (I thought) were installed prior to the upgrade from High Sierra to Mojave. For High Sierra a Trunk/Trunk and fixes/fixes install worked. Upgrade to Mojave Doesn't work.
Now, after the install of Xcode command line tools, DOES INDEED WORK.
SUCCESS: Fpcupdeluxe ended without errors.
Fpcupdeluxe has created a shortcut link in your home-directory to start Lazarus.
Shortcut-link: Lazarus_fixes
Lazarus MUST be started with this link !!
Fpcupdeluxe has also (tried to) create a desktop shortcut with the same name.
So that was my bad. Given that the install worked on High Sierra, I assumed that all of the necessary bits and pieces would remain installed when upgrading to Mojave. Not so.
To all those that have responded and offered advice, thanks you, apologies for the time taken, I have no doubt I will be asking for assistance in the future.
Kevin