Looks like you are missing the two switches on the right of the machine bed. One of them controls the power/light, and the other controls the speed of the machine. It could be that your machine is in low speed. Though it also looks like the bed has a hole for a treadle belt, so those machines may have a different switch arrangement. My machine doesn't have that.
Older Necchis had really close tolerances, so they require regular oiling, so it is also possible that your machine just needs a good cleaning and oiling.
If you didn't pay a lot for the machine, I would keep it and work on it.
The necchisewingmachineclub yahoo group has a lot of information that might be helpful, though you will have to join it in order to be able to access their files section.
http://groups.yahoo.com/neo/groups/n...tions/messages