Looking through the many pics, made me curious of the saddle brands on English bikes, specifically Raleigh. Perhaps an expert on deciphering date codes of the DL-1 can better explain but for a few years, there was an issue of quality by Brooks and Raleigh sourced elsewhere. Anyhow, if you install a new Brooks on your bike, you could say it was made with machines from the late 40's and early 50's.