Rehab for increased rents, now refinance and/or re-zone?

[Casey Marley]

I'm looking to get the most equity out of my property to reinvest and would like some input.  I bought a 1977 10-plex (only zoned for 8-plex) 2 years ago for $715k.  When I purchased the property, the current rents were really low for the area at $800 a unit.  I started rehabbing the units as the became vacant and then increased the rents to roughly $1150.  I increased rents on the non-rehabbed units  to $900-$950.  I'm looking to remodeling all of the units which would provide a higher rental income.  Is the annual income the main driver in refinancing based off of a new bank appraisal?  How difficult is the process for attempting to get the property rezoned for a 10-plex rather than a 8 unit max (R2M)?  How successful have people been in doing this and was it worth the money and time?  I'm guessing that this would make a significant difference for the appraised value during time of refinancing.  What would you do?