See the attached PDF article to help identify internal components of the 2465A Autofloat controller. Note that the Autofloat controller went obsolete in early 2016 due to parts no longer being available. The stock of 3915575 valves has been used up over the years and they are no longer available. The 3915651 (Apply and Release) valves are still available.
If your Rpt Isolation valve or Rpt vent valve make the Autofloat controller non-operational, you might be able to operate in limited modes, especially above atmospheric pressure, by disconnecting the Barometer (Rpt) manifold from the TEST pressure line and removing the Pressure Relief Valve from the end of the fittings connected to the Barometer. If you do this, you must reconnect the TEST lines together - bypassing the Barometer manifold.