Welcome to the best A body Mopar site on the web!
Just ask away.that ebay link, for me anyways,does not show the support in question.
As far as a parts interchange manual, there use to be a huge book some of the local wrecking yards had that showed what interchanged with what.But that was 15 years ago the last time I saw one.Most of the interchangeable parts knowledge comes from years of getting dirty, or lots of research from others experiance.
The members on this forum are Very knowledgeable, and are keen to help.