I would recommend introducing yourself to medium to large job shops in your area. Many of them subcontract work out that doesn't suit their production. Many times these machine shops have existing customer that they prefer not to turn down work from for the sake of the relationship. that same shop might be set up for medium to large batch sizes and a small batch run is a costly interruption to the normal flow. Often times, these shop will sub-contract these smaller jobs out. You'll need to offer a quick turn-around and offer excellent communication and follow-up.
Also, you'd be surprised how easy it is to be considered for work simply by asking. Almost every small manufacturing company sub's work out. Whether it is a maintenance shop at a small food plant to your company making "widgets".