Hello Joe and welcome to the forum.
Great to have another LH119 on here.
I wrote a fairly long post on parts, resources and the like on my show us your page, which details most of the online content that I know about. It might help you get started. The thread is here:
https://hiace-super-custom.forumotion.com/t4317-my-lh119I’m guessing that your dash is mechanical. A little later many Hiaces were fitted with fancy electronic dash, but I think that was after yours, no?
The clocks are not easy to get but I’d expect the speedo part was fairly commonly used across the Toyota range. Best way to check that is to use the EPC and the linked parts sites. Again all this is over on the post I mention above. This might mean you can get a set from a different vehicle and fit it in.
Some research needed, certainly.
If the speedo is the problem then it’s not a massive job to extract the instrument set and swap out this part. You do need to be careful though as the plastic is likely brittle with age and the electronics on the back of the clocks (and connectors) have probably become fragile.
There are two other sources of failure in the speedo that I can think of. One is the cable, which I believe is a fairly standard part. Again the EPC and similar resources will quite you. The routing of the cable is interesting and if the problem then replacing it will take you to places on your van you will be surprised at. The other failure point is the speedo drive on the gearbox. The manual (what I have) is fairly straightforward and common across many Toyotas. I understand the auto uses a more complex system, but again this can all be viewed on the EPC.
Hope this helps and please do read the post I linked above.
Cheers!