I revisited HSL's website in response to this thread. Apparently the original deal was brokered by the LCCA and it's back on! It looks like once again you can buy the disks, and for you Tinplaters, now there's one spanning the period 1900-1925!
I'm not personally interested in going back that far. But to have a more up-to-date reference collection, I wouldn't mind paying for one that covers 1995-2020. Didn't see anything like that on the website now, but we'll see!