Beginning with his first trumpet, Vincent Bach kept a record for each instrument built in his shop. These cards, known as shop cards, contained such information as the instrument's serial number, bore size, model number, valve fit, bell mandrel, type of bell brass, date of completion, date of sell, purchaser's name, and any other technical notes that might have been needed. By the time the Selmer Company purchased the Bach Corporation and production was moved to Elkhart, IN, the number of cards held totalled over 30,000. Below, we see the shop card for Apollo trumpet, #639.
Today, inventory is kept on computers, but each trumpet manufactured carries its own inventory card, as seen below with this card for a brand new LR180 Model.
David S. Miller