can easily design a replacement circuit board to go inside the existing housing. Conversely if the housing can be obtained easily then I think a slot has to be cut out, but that's all achievable. I don't know where the housing comes from or if the mounting holes are necessary/used/correct. If someone could supply that info then that would be handy.
TalkMorgan comments request a simple device that is more reliable, so I would propose removing the current sensing circuitry, the CD4072 and also connecting the repeaters directly to the indicators. For some bizarre reason, they are independent circuits!
