I tried a box of 1968 Tri-x this summer. Since I had only PMK as a developer, this is what I used. I was never able to print through the fog in order to get proper contrast. When I extended development times to increase highlights, it seems the fog density just came along with it. This box was not cold stored, but was on a shelf where the climate is "warm" six months of the year. A different developer would have helped, but I ended up returning the box with a "thank you."