In the context of the conversion of Osip Mandelstam, who was baptized as a Finnish Methodist, I quoted Vladimir Jabotinski, who in his novel The Five tells the story of a Jew from Odessa who contemplated conversion. He was given the advice to do “as everybody does” and go to Vyborg to see the Finnish Lutheran pastor “Pihko”.
The attached article by a Finnish theologian André Swanström analysis the story of Mandelstam’s conversion and also tell the story of several Finnish Lutheran ministers who baptized hundreds of Russian Jews around the turn of the century. Among them the most active one was a man called Arthur Pihra, who was disciplined, as were the others, by the diocesan chapters, for transgressions against Church law.
Thus it seems highly likely that Arthur Pihra is Pihko.