Hi Astrosammy,
Try to use
EasyTiler, this is an excellent application for this purpose (see the readme for how to use it).
At some point google rejects the manual download of images, but most of the time you can download everything you want. Otherwise you can try again the next day.
There are a few problems/bugs that prevent me from finishing some addons (using EasyTiler), however this is only if you have huge detail for large areas. In general, the utility works okay.
regards,
mcduck