By what mechanism do cephalopods regrow limbs?
well gastropod mollusks use Epimorphosis, so it is likely cephalopods use the same mechanisms. Basically all triploblastic organisms use this mechanism so phylogenic bracketing points towards it as well.
morphallaxis is generally restricted to very simple organisms.
Regeneration of the visual system in gastropods (Mollusca)
Oksana Tuchina  Victor Benno Meyer‐Rochow
Neural regeneration in gastropod molluscs
Author links open overlay panelStacia B.Moffett
Regeneration of the visual system in gastropods (Mollusca)
Oksana Tuchina  Victor Benno Meyer‐Rochow (alternative link)