I get a lot of my restoration work from the local frame shop. It all started when I went to him to get a restored job framed and we got talking. He keeps an example of my work in his shop and if sombody asks about restoration he gives them my number. I didn't want business cards left there he simply writes my name and number on the back of his own card, it's good advertising for him that way. I refer all of my custom framing jobs to him, it's a good arrangement. If the customer wants me to organise the framing he gives me a "professional discount" so I make a little on the framing to cover my time and running around costs involved in getting the job framed.
I have found that working with one framer is best as there is no conflict of interests that way. And also most other framers in my area offer restoration as a service themselves so they are not intersted in refering work to anybody else.
Hope that helps