But MLJ also corrects the RSV, which I think they had in their pews
Yes they had the RV under Campbell Morgan and MLJ switched to the KJV because the Biography records that MLJ thought the KJV was a better preaching Bible.From what I remember of Iain Murray's two-volume biography, I think that it was the Revised Version that they initially had in Westminster Chapel. I am nearly also sure that MLJ changed the pew Bible to the AV (probably because the RV was no longer widely circulated).