I don't think I was very clear describing the specific part, but the last few guys picked up on what I concerned about specifically (other responses had some good painting tips though).
This page shows the trim bit I mean, just fyi:
http://www.rvmagonline.com/tech/1402-project-terry-part-4-interior-finish/photo_03.html#
They seem to have done what Paul suggests, which doesn't seem too bad - just cut it off and use normal quarter round like you would in a house. This will be a good approach for laying down some replacement flooring or carpeting too.
