Medresco (MEDical RESearch COuncil) and the Department of Health & Social Security (later NHS) provided free ear trumpets from 1948 to 1976.
Medresco hearing aid type numbers all began with the letters "OL" followed by some numbers.
Date marking of later Medresco trumpets follows the simple pattern of MONTH YEAR, some trumpets have a secondary date. The arrow () is a UK mark used on government equipment, you may be more familiar with this older broad arrow , but I use the 1980 standard.
oftens displays 2 dates, I suggest '851' is the NHS-required build date and 'SEP 1951' is a later added ship date.
This list is to help assign pictures to model numbers. We know that the OL series was started just after the NHS was created. The oldest NHS/OL trumpet recorded here is January 1949 and the latest is April 1976, HAM has 776 on an OL38001.
Starred items are part of my Wish List