The pre-existing release is a CD re-release, but when I’m trying to enter the original I’m not given the opportunity to select “Vinyl”, the “Format” is automagically set to CD. What am I doing wrong?
If you’re adding the new release, and select an existing release on the “Release Duplicates” tab, the format will be set to the source’s format, CD in this case. But you should now be able to click on the format and change it to a different one. Is the dropdown box not working for you?