Help setting author for posts: Poetry Publication: Correct credits

Hello,
I started using WordPress for our poetry magazine a while back, changing from another CMS. So, each poet that we publish has an account on our wp site. I used to be able to use the ability from the quick edit link. I moved the site to a new server and so I don’t know if I forgot to install a particular plugin. My searches of the plugin directory have not revealed anything that would do this.
What I want is to list with each poem, the attribution of 3 co- editors, 2 publishers and one author. The author is never me, when I’m publishing someone’s poem. I found an old forum question from 2009 that said this change could be made from the edit display of the post. Does anyone know of a way to do this? An extension? I’m not sure what to use as my search strings… Something like admin assign author.
Note, I did start adding fields with Advanced Custom Field. With that I added fields for 3 editors, and 2 publishers and I can add an author field. This is not yet showing up in the output and I have the JSON API plugin which I use to create a mobile version using Jquery Mobile and JavaScript. My mobile web app works great when the author is correctly assigned. Again, I used to be able to do this and with the previous issue of the magazine, I get a nice JSON feed with title, and author and etc., which is easy to parse.
Ultimately, being able to get the custom field data in the JSON feed is the best solution, but if I could assign the author of the post, which is a poem, to match the person who wrote the poem, then, no change in my app is needed. So, that’s the easiest fix.
Thanks,
Bruce