Cannot Get Image to Display Any Way Other than Centered

I’m not sure if this is an issue with the plugin or an issue within MC itself, but I can’t get the image, no matter what I do, to display anything other than centered and full width of the available space.

I have tried:
– Setting the image size within the Featured Image plugin (it will swap out the images but MC still blows up the image to 100% of the space)
– Setting the image placement within the Featured Image plugin (it does nothing)
– Adding the appropriate CSS .mcRssImage with the width attached as !important (it will look right in the MC previewer, but will not work in the actual email)
– Adding the appropriate CSS to float the image left or right (again, looks right in the MC previewer, but does not come through on the email)

Essentially I am just trying to get a smaller image, around 300px wide, to float right with the content wrapping around it.