Hello Russ - you are absolutely right and I thank you for your help.
Unfortunately the new "product" images did not appear on the page and that threw me for quite some while until I discovered that the images supplied with the solution support files now did appear. This clearly pointed to missing images though I was sure they were in the images/detail/ folder because I could see them. Renaming some images did not appear to have any affect so it became clear to me that there must be product images in a folder that I was not seeing. The light bulb went on and I took a look at the testing server in htdocs/images/detail/ where, for reasons I am unable to fathom, the "new" product images were conspicuous by their absence. Manually copying the missing images to the folder on the testing server fixed the problem.
Another example of "don't blame the tools" - in this case the WA application.
Of course I still need to figure out why the images files did not automatically transfer onto the testing server, but that is not a DA issue, its another "me not doing something right" issue.
Thanks again Russ for your "spot on help".