Even having increased the memory allocation, the WordPress importer failed to execute. The Gorse Fox went to Plan B. This plan, as recommended on the internet, was to split the export/impot file into smaller chunks using some Python code. Seems simple enough. Needless to say, it wasn't. It failed. The Gorse Fox was getting fed up with the amateur errors that seemed to surround the environment. He decided to look at the code. He is a bit rusty with Python (in fact he's never been fluent), but it was soon evident that the author hadn't thought through some basic changes that may be included over time. Two lines of code needed to be changed to accommodate variations in format, et voila, the code now works.
More than 12,000 posts were imported into the new blog... the only problem being that they do not correctly link to each other, and some (only a few) do not have the correct post date. Clearly the Gorse Fox has a lot of coding and fixing to do when he gets time.