In the OP & the first pic - I believe (but could be wrong) that there is no gold in the chips on the right (double row of chips) the bond wires in those chips are aluminum not gold
they are EPROM chips & if you look through the window on top of the chip I believe you will see that the bond wires are silver (in color) which means they are aluminum bond wires (instead of gold in color)
Edit to add; - the chips with the gold caps &/or with the gold (plated) legs are the only ones really worth processing (IMO)
Kurt