Have the Prochem hidey hose hand tool,,but think I am going to walk.
And yeah I lowered my upholstery cleaning price a bit,as was not booking any of the quotes I was doing.
Although I did do £400 worth a couple of months back,for someone who lives opposite me,in the biggest house in the village 
That would work but ideally you want to spray the fabric with it from about 2 feet away after a good spray with Dri Pro and brush in to give it a moisture barrier.
A good vac off. More DriPro (or equiv) brush vac, towel, air mover.
As Lindsay said it takes a fair amount of time but the results will be good and its fairly fool proof if you have good upholstery cleaning skills/experience.
Obviously you need to be getting good many so you can afford to put in the time.
I would go back to the client and explain that you have done a little research and found more about this piece and are worried that the next guy might not be so cautious. Explain that you may need 2-3 hours to hand clean it and tell her the price.
If you want me to talk you through this give me a call during business hours. Always happy to help.