If you read my posting above, you can see I've already got Tesseract installed.
The Google search link provided by knudfl does however pull out a webpage that does give useful suggestions for programs and also gives some essential details about Tesseract - it only works with tiff files.
https://askubuntu.com/questions/1626...t-ocr-solution
"To run tesseract goto terminal and type the following
tesseract imagefile.tif outputfile.txt
Tesseract can only read a TIFF file - if you've got a JPEG or PDF or whatever, you'll have to convert it. Also, the filename extension must be .tif, not .tiff, otherwise tesseract errors out."
I have already solved my OCR problem but other might find this useful. There appear to be many other OCR programs apart from Tesseract - no idea which one is best.