I founded 51L many years ago but ill health forced me to sell the venture ( parts 1 and 2 - a long story ) to David and Andrew. The range covered many of the pre-grouping companies from Scotland to the South Coast so they will plenty of variety for your modelling period. Kits from Andrew are readily available but not so from David. If do need something from David, with whom I’m In regular contact, I will see what I can do for you.
Please do get in touch with me if I can be of help with you project which I will follow with great interest.
Regards
David Scott