Yeah, that is confusing. Thanks for pointing that out. The reason that it only shows you the "Original" version when you click "just take me to the game" is that the original is free, but in order to download the latest version you must pay $2.00 or more. It's annoying that even if you own it, itch just shows you the free item.
If you do own it, however, the page does have a "you own this" banner with a "download" button which DOES take you to both downloads.
I think I'll just add the Jam version to the $2 tier as a bonus, since it's quite far behind the latest and doesn't really sell it well.