Many thanks!
I just uploaded the full modules folder, overwriting the 'clone' one.
Unfortunately the tuner is still not showing up.
I must conclude that the new tuner is either broken or this does not work for some reason. The only other thing I can think of is that the tuner is a new revision not supported by the older images. And the only way to figure all this out is to get hold of a original box.
You have been surprisingly supportive, and thank you for that. But I think the party ends here, we should not spend more time on this.
Just to add...
When I install the old DVB-C tuner in the box with the modified image, the loading also stops half way. So it is definitely some sort of driver issue.