belg, do you really mean 1950? Not 1905?
I doubt if there were any industrial enterprises in 1950 still using waterwheels. Of course there might have been some grist mills way out in rural settings using water power, or I could imagine even a sawmill complete with waterwheel for a logging layout. But machine works???
I didn't find any 'modern' waterwheels, when googling around. The most recent was one (lousy) picture of a German planing mill which was closed in 1933 and now waits to be renovated as a tourist attraction.
However, here's a useable drawing I found of an 'undershot' waterwheel. The axle would protrude through the wall of the industry building behind the wheel.
I guess this type is easier to model than a waterwheel which is fed from above (and should have closed pockets for the water). Just a hint for anybody who looks for easy-to-do waterwheels.
Ron
Ooops... forgot the picture