Thank you for your considered reply dempson.
1. I use Adobe CS5 suite for graphic design and have been running an 2007 iMac for decades in order to do so. I have a considerable library of design components which I wish to preserve and have access to. After Lion, CS5 apps, Illustrator and Photoshop, get the odd glitches in later systems. I am trying an upgrade to a 2011 iMac but that has GPU issues which make the future uncertain.
I have a 2019 iMac for general use and have adopted Affinity Design suite for current graphic work. Affinity imports all Adobe Photoshop and Illustrator files so this appears the most sensible option.
2. The VMware Fusion idea is an experiment to see if I could circumscribe iMac 2011 hardware weakness with a faster/better option. I recognise the potential for incompatibilities running software in VM. Only way to find out is to test.
3. Your advice matches that of Colarado Marmot and I shall try that out and report back. I appreciate all your background comments. In the past, between iMacs, I have used Ethernet to get more speed than USB2.0 or Firewire offer and that has worked for importing cloned systems, but Migration Assistant as you know, is more selective.
Thank you for the extensive background considerations. I realise that being a dinosaur with old applications asks for trouble but the Adobe suite does all I need. Unfortunately IT progress demands that once you have achieved a pinnacle experience, another route must be found to the same destination so the economics of obsolescence can generate continued profit for the manufacturer. Happily, I continue draw and paint without fear of redundancy.
Many Thanks.