Hello,
if you want to buy an older Cord please notice that between the Rolleicord V and the Va the fokussing knob was changed from right to left. The Vb also has it on the left side. All models befor the Vb had a rather dark ground glas viewing screen, but it can easily be changed against a modern one cut to size from a RB 67 (maybe the fokus has to be adjusted then).