Sorted!!
Apache Settings already set up for symbolic links and hello php worked ok
(For those with WHM access it's in Apache Config > Global Config > Directory "/" Options section)
What was throwing me was that Templates doesn't literally say 'symbolic links
It's the 'special: Special Copy' setting that is needed.
So here's the instructions for what I needed in case anyone else out there needs it too!!
To replicate the master website with specific "/images" folder and share the joomla "/templates" directory, you need to create a JMS Template rule. The following instructions assume that you have sever settings that enable you to create Slaves in the root directory (not the public_html of the Master Site) and that you have used and created cPanel addon domains and created databases with unique users attached to them BEFORE creating the slave.
JMS template
template ID = replicMaster
Domain = www.{site_id}, {site_id}
Select the template site = <master DB>
Put a default rule for the "new site prefix" = {site_id-2}_
Deploy directory = /home/
servername/domains/
addon_domain_url/public_html
In the "file and folder" tab.
Select that you want the "image" action = copy
for the "templates" the action = "special: Special Copy"
Once you have the JMS template "replicMaster" created, you can use it to build the slave site.
Site ID = domain.com
Select the template "replicMaster"
Enter a site title
Put a new DB name, DB user, DB password.
The result of this will be slaves based on the Master but that are editable in terms of content. In my case, my slaves are all local directory sites so the content needs to be unique to each site...however the 'look and feel' of the site needs to be the same.
Cheers Edwin for your (as always) excellent support!
Paul