Wayne, thanks! Yes, Shutterfly has no realistic way to download full-res photos, although the site seems to maintain them in full res. Really, really dumb. So that won't work for us. We have some group shots that have value at full electronic resolution.
I looked into Smugmug which permits full-res downloads. However, it doesn't look like it permits UPloads from members of a sharegroup, so that doesn't work for us.
Case was a very technical school 40 yrs ago, and you'd think Facebook would be no problem for my Brothers. But we've struggled in promotion because only ~1/2 are even on Facebook so our Group there only spoke to half our target. So, Google+ is not an obvious option.
We did set up a separate Joomla site which is ok, but clumsy for commenting, and permitted only site admin to upload photo's and files. (Of course, FB has the same limitation. But because half our target won't go there, it's not really an option for the future anyway.)
Their objection to FB seems more social privacy and time value than technical. So, Google+ could work where FB did not. We can probably provide some linkage to it from within the Joomla site, with simple instructions.
Thanks again for the feedback. This is not an area that I've paid much attention to.