My RV parts place in Missoula MT found that their supplier had one in stock in their warehouse in Utah, and ordered it for me. It came in a week, over 4th of July which delayed it a bit.
Prior to ordering it from them, I googled the Atwood number and found several places on line which sold them. The cost was about the same. I like to give my local RV place as much of my parts business as possible so they will stay viable and be able to get things for me when I need them. But, if you are having problems finding it, on line is the way to go. Mine was an Atwood 88007. Just Google it.