It is a 29-4 for all intents and purposes... the SV as I understand it is an indication of a special order varient. (Could be the motor addition in fact.
The manual for the 29-4 will be fine for this one.
I have purchased one for about $150 but they seem to sell for more like 3-500 (LOTS of folks ask 800+, but most just sit at that price)
Cleaning it, oiling it, and making sure it sews, is the only way to get those prices, BTW