The 1052 gear is 28 teeth, ive got one here Dunc
I did ask Harris about the frame number, the reply was its a F1 race bike from the early 80's, but they didn't keep records of who bought them, he thinks it was for a kawaskii probably a 600 or 750 but wouldn't confirm or deny either
anyway its looking ace Dunc, this is what i hoped to do when i bought it, glad you are doing it