Just revived this old thread to say thank you to uart and phred01, both of my chargers failed a week or so ago and a quick google found this thread. Ordered the diodes from Aliexpress, they took a week to get here, soldered them in yesterday – the circuit boards were the same as the two in the photos, diodes vertical in one, horizontal on a white board in the other.
Charged two 4Ah batteries yesterday, will do two 2Ah ones this morning.