Help needed to ID corals

[PaleoOrdo]

I would like to start present some of my coral finds, or what I believe are corals. The first are from Tyrifjord lake area in Norway, I am uncertain of the formation, but I believe it is Ordovician of age. Although one paleontologist told me that the area has Silurian sandstones of Early Silurian age, a geological map I found also includes some Ordovician outcrops. These I presume are favosite corals. Is it possible ID their order, genus or species? Their sizes are about 10-12 cm long. I am not sure these are sandstones or limestones. First rock:

Second rock:

Thrid rock (this I left in situ):

Finally, from same location:

[PaleoOrdo]

A more clear photo of the first rock above, from the other side:

Edited December 19, 2021 by PaleoOrdo

[Rockwood]

This looks like Favositid coral to me. They did originate in the late Ordovician, but were more common in the Silurian I think.

[PaleoOrdo]

Thanks, Rockwood, happy to know the right genus.