In case you hve not found this one previously:
Here is a link to some Bridgeport machine discriptions, that a used machinery dealer keeps on his website.
http://www.machinemanuals.net/web_pages/bridgeport.htm
If you hunt around, he also has a, little used, discussion board, including Boss machines, that you might glean some info. from.
http://www.machinemanuals.net/web_pa...ge%20board.htm
Russ