A couple of weeks back I bought a similar one at a yard sale. Several people mentioned that it was a Blackside. Mine is a 128 but I wonder what the difference is between a 128 and a 128-23? According to the serial number mine was made in 1951 but it does not have the centennial seal. I did not get a manual with mine and the box lid is missing the lock mechanism but otherwise in good shape. Have not tried to just the shuttle bobbin yet but will eventually. Enjoy your new machine.