I've decided to simplify the website a little by disabling custom image scaling factors. Previously, on the top right of every page were three icons which linked to pages where the sizes of images were either larger or smaller than what the current page presented. This has been disabled.
Now, all images displayed on pages will always be presented at half their upload size (for example, uncropped landscape photgraphs will be 450 x 300 pixels) accompanied by a direct link to the original unscaled image. Some pages also present images alongside paragraphs of text, these images will always be scaled to three-quarters of half-size (IIRC).
This takes some of the functionality away from the site, but I believe very very few people were even aware of the custom scaling factors. On the plus side for me, it free's up some disk space - there will be fewer scaled images to store which means more content can be uploaded. Additionally, search engines will have fewer URLs to trawl as the 's' parameter is no longer generated - which is good all round (research SEO and website bandwidth for why).
Of course I have not completely disabled the custom image scaling. Perhaps in the future I will find a host which gives me much more disk space and then I can reenable full image scaling by simple changing a setting in the main.layout 'page template' file for jwm-art.net.