This machine appears to be complete (w/bobbin, bobbin case & a decent looking electrical cord). It is in a handsome & unusual sewing table. I am looking for a threading guide & sale value.

My guesstimate and that's all it is, would be about $ 350 with the nice woodwork. I suggest trying eBay to get some better comparisons.

As for threading, I'll try to give you an experienced guess according to what I can see in the photos.

From the spool on the pin on top, run the thread to the left to the button-looking thing with the screw in the middle. I think this may be the tension, unless there is one around the side or back, which I cannot see from the photos. You should be able to put the thread behind it, probably laying it on top and pulling down. Then there is a bar below that which moves up and down. There should be a hole or slot in it where you can put the thread. From there, go to the bar on the side, which moves up and down, and put the thread through the hole. There is something on the side close to the needle, but I can't make it out. It could be a thread guide (maybe something else?), and there is a thread guide on the needle bar. Then through the needle, probably left to right.

The bobbin thread will have a certain direction to it, but you will have to give more photos for me to help you on that one.

The ultimate test is in whether it sews correctly, or tangles.