As a reply to a comment, on 18th May 2017 Peco confirmed on their Facebook webpage that the next L&BR R-T-R coaches to be released are the centre observation and all-third coaches, both are which were (at that date) currently in tooling.
The “Third Centre Observation Coaches” are L&BR No's 7 - 10 inclusive / Southern Railway No's 2465 – 2468 inclusive; and the “All Third Coaches” are L&BR No’s 11 – 14 inclusive / Southern Railway No’s 2469 – 2472 inclusive. Thus there is scope for sixteen (16) new Peco L&BR R-T-R products to be released in future weeks, months, years, decades, or only God knows when?
Chris