Congratulations Roger. Smoothing out the pace is do-able.
My TWH only did a pace and a trot when I got her. She was a hard case to
change, but with patience we did. She had a ewe neck and that nose
was up in the air. We have since migrated her muscles from the bottom of
her neck to the top and she now does a running walk, stepping pace, saddle rack
and rack. The thing that helped her was free lunging in the round pen and
rewarding by taking the pressure of when she lowered her head. Lots of praise.
After that was a done thing, I did the same thing when she gaited. She is
so enjoyable to ride now. Also the many miles of walking, walking,
walking and hills, hills, hills.