On going saga of replacing 67 GTS master

So years ago when I replaced it I went to the parts store got a master installed it and that was it. Not now. First one the cap leaked. Second one was in a box that said it was a manual brake master but I think it was for power brakes since it was overall much larger and much higher pedal effort. Third one I looked at before taking it and it had a trail of brake fluid from the piston right out of the box. I didn't trust it not to leak so I refused it and they are getting a fourth one.