Yes the picture is correct but what they send you will not be, at least in my case.
The picture shows disc/drum master, what I kept getting (ordering the P# for the disc/Drum master) was the master that had equal front /rear reservoirs or drum/drum. I have a 67 Barracuda with the same as your duster and searched all over for the correct unit, tough find.
Yes they say use it, and it may work but not correct or looks correct. Disc/drum should look just as the picture you see. Small/large reservoirs. They sent me 4 times the wrong one until finally it was admitted they did not have what I wanted. In the end the guy sent the correct one say it was the last re-man he had, for the trouble he said keep the others as It wasn't worth the shipping return. (Can to US) So, I have 3 of the others if you wanna try? The picture above can be power or manual operation and is correct for what you seek as far as I am concerned. but the picture is not what you will get as I found out. Best to ask them.....
Try The right Stuff. They have a good catalogue and are helpful.