Well, I wouldn’t try and do it that way.
Just start with the level, as is.
If the player changes something, destroy the original actor, replace it, and record the class and transform of the replacement.
When the level re-loads, apply your saved info by destroying the actors and replacing them with the correct class, which you transform.
It gets much easier, if you replace all the meshes with blueprints, that look like meshes, but can record what you do to them. Then, on reload, each blueprint just transforms itself.