Automatic draw off probe

[Whitcomb Family Farm]

I have a greytron adoc draw off but I am down to just one probe that works and have to move it when I switch sides. Does anyone have an old draw off like this one laying around that they would part with? Leader hasent carried parts for this unit in 10 years. I was able to track down a probe from the owner of marcland but also dosent work. What makes these probes tick is it something that could be replacated?