Odometer only counts tenths

Good morning all, greetings from sunny Texas. We have an 89 Pao and the odometer at some point has stopped turning over whole kilometers. The tenths dial in white still rotates and the speedometer is fine. This leads me to believe something has gone awry inside the speedo/ odometer unit itself and isn't a cable/signal issue. Before I pull it out and dismantle it, has anyone run into a similar issue before? Or have any fun tips for this process?

Thanks in advance,
I wouldn't know how to fix that, but if you were a dodgy used car salesman that sounds like a dream

1989 would probably still have the cable type odometer, and I would guess that something has broken between the 1/10ths wheel and the kilometer wheel. The old analogue counters just used a bit of plastic or ceramic or something to nudge the next wheel every time it got to 9 I can't see it being clockwork gears.

Perhaps it's got some dust or dirt in there and it's come off the track?