I have collected all 4 artifacts for Drogan, but also seem to have an option of selling these for a fair amount of gold with some of the merchants. Is there any advantage in hanging on to them instead or giving the whole lot to drogan?
Do they have any value beyond ch1?

Umm, I just finished it again. I gave them all back, but I think you suffer some alignment issues if you sell them.

Decided to keep them in the end - and now in ch2. The hand vanished anyway, but the mask is quite useful, and the tooth does have some use as well ;)