I should have known that the master of woodwork Matthias Wandel would have also built a counter and he did it much better than I did. This counter has a Geneva drive between the digits so the upper digit only moves 1/10th of a rotation each time the lower digit passes zero. My counter is a bit flawed, the tolerances weren't tight enough so it gets a bit sticky as it increments. I can rebuild it so that the parts overlap in a better way and avoid snagging.
I took a short video of the two different counters in action but for some reason my camera was only letting me take 4 seconds of video at any one time.
I improved the counter wheels, each number has a tab which fits into the end wheel, this ensures even spacing around the wheel and that the numbers are all square.