For anyone, if not Chris, to answer!
After reading through some other posts, I found one other user to have the same issues, but only be told to look under the video, and above the comments section. I've tried disabling cookies, ad-blockers, changing internet settings, and simply trying different browsers; but the link or file download box doesn't appear for the calculator. I use Chrome on my 64-bit HP. Maybe I'm over-complicating things, but I just can't find the route to that calculator!
Whatever input you have helps,