原稿 - オランダ語 - De ondergeteknde geeft bij deze volmacht aan de...

The last one! This one is very formal and quite hard for me to translate into flawless English. I did my very best to translate all terms correctly, but you might encounter a minor mistake.

The undersigned hereby gives power of attorney to the persons employed at the premises[? office] of..., as together [as well] as every one of them individually, to sell and deliver for and on behalf of the undersigned.
To this end:
- to draw up the notarial act of delivery and to sign;
- to receive the purchase [the sum of it, the money] and to grant discharge on it;
- to hand over the sold [used independently: the sold item] in ownership,
in general to do everything more what the authorized deems necessary and/or desired, with the power of substitution.