In completing steps 1-4 of the Iowa Legislative History process, you will have likely found most of what will be influential to the courts in determining intent. It is possible, however, that by continuing the process you might find something relevant for your particular piece of legislation or obtain additional useful background or other contextual information.
Look for a compiled bill history to see what actions each chamber took on the bill. If a compilation does not already exist, compile your own using the House and Senate Journals, which record actions such as the introduction of legislation or votes taken in the House or Senate. Note that the Iowa House and Senate Journals do not include floor debate. If the governor vetoes or item vetoes legislation passed by the General Assembly, a veto letter will typically be issued and can be found in the House and Senate Journals.
Bills available from the Iowa Legislature's website (1995 or later) will include a list of actions taken and will link or cite to the journals. Look for Current Bill History or Complete History.