Replace Sensor Systems Niveau Watchman with Watchman Sonic?

[sammc007]

Can anyone advise if a Watchman Sonic oil tank monitor can fit the hole used for an old Sensor Systems Niveau Watchman? I want to replace the old hardware and the new Watchman Sonic needs a 32mm hole. Obviously I'd rather not have to drill a new hole. I don't have access to the tank at the moment to remove the old unit and measure the hole.

Thanks for any help.