Got it! Images missing, but text should be enough.
https://tvwbb.com/showthread.php?53317-HeaterMeter-Hardware-v4-2-4&p=637282&viewfull=1#post637282
which leads to https://web.archive.org/web/20150213043730/http://store.heatermeter.com/products/heatermeter-v4-2-broken-pcb