I need to implement a utility that would help changing content types in a consistent manner and mapping the old and new Form variables correctly. For instance, previous form used FormVariables to ensure attachments of certain purpose like a document set. At some point we need to use another form in the same list, and the attachment names may need to be moved to other form variables.

I understand that I'll need to do some sort of an XSLT transformation, but if other content types are involved, I'd like to the utility to be smart enough to auto-map similar fields if they only differ a little bit.

Any hints appreciated.