Hello again Eldorado (such a cool moniker),
I apologize, I should have mentioned that if you go to your Plugins tab > Extrude map That will extrude the images from the brightest (most intense) to dimmest (these images must be in 32 bit format) in order and output in 8 bit format, therefore each image you extrude will contain very many images. Only work with two at a time and then ensure you have the same number of images in each stack prior to interleaving them. Depending on your needs you may only need to use 4 images. Front, back, each side.
With that being said, there is a Open Source software named “Meshroom” which you can download for free which is designed to do exactly what you desire automatically. That would be much better. Also there is another software named “Blender” which would be easier than Fiji/ImageJ.
There are no silly questions, and no truly simple answers.