Hi?
I do not know of any specific makers of L&B paints, but would suggest something from the Phoenix Precision range would do. ?You may have found this article on line -http://www.009.cd2.com/liveries.pdf
This rightly points out that no records survive and black and white film is notoriously difficult to interpret. Add in light conditions, reflections, scale effect and distance effects as well as weathering in the salt laden wet west country air, then no-one can guess at any 'correct colour'?
There is an LSWR salmon in the phoenix range, with a selection box of browns reds and creams ?They are excellent paints (no personal interest apart from end user) which I now tend to use exclusively. ?Plus mail order very prompt (if not cheap as they correctly use courier not the GPO for solvent based products.)
Paul?
Paul Holmes