Finally resolved. You can install Lightroom 10.4 (32 Bit version) on Mojave and with the help of Adobe techical support on line they managed to install it on my PC. The process was quite lengthy and it involved a number of changes to settings etc. They did however struggle to upload the most recent catalogue and told me that it was too large and that in future I should create a few smaller catalogues. The down side is that I lost some of my recent keywords and adjustments. Rather annoying but I am now running it on my computer.