In Czechoslovakia production was soon picked up by Skoda and Tatra. Together with captured and abandoned units they are put to good use in the new Czech army. The picture above seems to be an unchanged 251, except for it's light guards. Apparently they stayed more or less unchanged till circa 1950-55. Then the design is changed. It gets the designation OT-810. The hull is slightly longer to take a Tatra diesel-engine.
These pictures from the thorough article in the magnificent magazine "Wheels and Tracks" shows some of the changes and characteristics of this stepchild.
These pictures were taken after de-mob, on transport to the west.
The top is closed. It gets a new dry chain,
(sprocket from the manual)
replacing the lubricated one. The air cooled diesel gets its cooling from above. The hull is back to /c in the rear and is altered to get filters and other stuff for protection against chemical warfare.
The soldiers using them called it hitler's revenge.
Only a few have made it into museums. Most of them were cut up under the disarmament. Considering that, you could call it lucky that some will survive as 251/C and 251/D look-alikes.