Table and column name changes post database switch to postgresql in code

We have a very old application with multiple databases. Recently we decided to make a switch from MSSQL to PostgreSQL. During the process we decided to keep all the table and column names in lower case. This affects our code a lot. We want to go with minimal change approach.

Problems :

1. Table name changes - We thought of overriding getters and setters for the table_name in model to avoid changes at many places. Creating a module and then including that in all the models was one option. But our setter can't get control because of "ar-octopus" gem. It actually hijacks the setter for table_name. So this approach fails.
2. We tried mapping dynamic methods like "find_by_UserID" to "find_by_userid" by overriding "method_missing". But dynamic_matchers in activerecord has marked the method as private, so this also doesn't works.

The only option now seems to be refactor the whole code to suit the table and column name changes. But we have used queries, direct column accessing like @person["Name"] in views as well and use of many dynamic functions like mentioned in point 2. So even after refactoring the whole code and testing it completely we wouldn't be sure whether all the code has been updated properly or not.

We want refactoring to be last option. But, don't know any other better way.