Frogloks can now worship Innoruuk and using the note from the DE in the EFP tunnels can gain enough faction to do this quest. Unfortunately, the reward does not list Froglok as a usable race and is therefore not equippable. This item has to be equipped to be used.
The first part of the Disciple Symbol of Innoruuk quest generates a single use halfling illusion mask. Strangely, the Skinned Halfling Face Mask IS Froglock usable but the Disciple Symbol of Innoruuk is NOT. I have not yet finished the Regent Symbol of Innoruuk for my little Inno worshipping Frog Cleric but have little doubt that it is also not Froglok usable.
I suspect this omission is an oversight. I will petition in game and recommend others do the same.