Although the knobs where the correct ones, they did not fit over the stems correctly.

I used the blow torch to heat up a small screwdriver till it was red hot. I then quickly applied it to the inside of the new knobs to make the shape more accommodating to the stems size. Once I thought I had about the right size, I heated the screwdriver again and melted the inside of the knob again and quickly pressed the know on to the stem and molded the inside as best I could to the stem.So far so good. Everything is working again.