How to handle conflicting instructions when applying for a grant? I'm applying for a grant renewal. There are subtle and not-so-subtle differences between the solicitation document and the submission instructions document with regards to which materials (e.g. the proposal narrative, personal statement(s), CV(s), research schedule, budget, transcript(s) for student(s), etc.) are required for new proposals vs. renewal proposals. 

Obviously, the best path would be to contact the funding agency to ask for clarification. 

How might one proceed if contacting the funding agency to ask for clarification isn't an option? 

Should I assume the solicitation as written overrules anything else? Would it be best to just include all materials mentioned in either document, or does it hurt to include "unsolicited" materials?
When relating to granting agencies, I would say that, as a rule, it is not recommendable to submit more documentation than the one they are expecting.  

I would first make sure that the guidelines you are reading are up-to-date; you'd be surprised on how many times they are not. Once you've done that, consider whatever is written as the truth. If it is renewal you are after, restrict yourself to whatever instructions for renewal they have.

Of course, it will depend on the agency, but in my experience if something is missing either the automatic upload service (if that's the case) or someone from the agency will contact you to make sure everything is ok.