Question about restoring the landscape heightmap

Okay so I have a landscape that I have imported a heightmap for, I have been doing some sculpting on it, and it is pretty easy to undo mistakes if I make them on the last few strokes. But let’s say I open the file on another day and decide there is an area that I liked better on the original height map.



Is it possible to restore the imported height map, to use a tool to “sculpt” back the orginal height map? Theoretically all of that data should be stored as UE4 has the height map data from the texture. One way I could restore it would be to re-import the height map. But that would wipe all of the changes I made to the terrain and put my back to square one.