Just seen your posting.
Thought you might be interested to know that the register for the Greek necropolis at West Norwood Cemetery in South London records Leonidas Bistis as being buried there in 1924. (I imagine the original plot in Ireland had not been consecrated in the Orthodox tradition.)

Notes in the register would be consistent with the story of his exhumation from Ireland. There were several other people for the 'translation'. As far as I can tell there was never a memorial erected for him.
We can be contacted at www.fownc.org