I am new to all of this as well. I recently found a Pfaff 1245 on Craigs List. The grease housing was missing also. I cleaned up the machine, readjusted everything, and mounted it in a 3' X 6' table. I just use an acid brush and apply grease to the gears often. Seems to be working out just fine.
My machine came with a 3400 rpm clutch motor. Way to fast for me. I made my own speed reducer, and slowed the motor way down. I think that if I keep the gears greased it will be fine. So far I am really happy with the Pfaff. I am now trying to figure out, needle/thread and tension combos.