DM520 bootloader

I have a DM520 supposedly original. It runs original images quite happily, but as I am not trusting the supplier and the OriginalDreambox plugin shows it as not original I fear it is probably a clone with a very good sim. By the way it does not have a sim card but a chip. At the moment it is running openpli 5 from pli.images.net. It has a rescue loader identified as 102 but the latest rescue loader from the dreamupdate board is 103. Does anybody know if updating the rescue loader might cause problems to not quite original boxes? Might it interfere with a clone sim?

Thanks Master G. I have tried several original images and they all work fine but I don't understand why updating the rescue loader should affect the tuner. Is that what you are saying, that if I change the rescue loader an original image might not recognize the tuner any more?

If I then run into this problem what clone image should I then try? There seem to be only Japher or sim2 images for the 520. Any other?

Last question, if I update the rescue loader can I then downgrade back to the 102 version if things go wrong?