Keystone Advisors - is a premier business sales and acquisition advisory firm serving the Greater Philadelphia area and Delaware Valley. We specialize in small to medium sized businesses with annual revenues between $500,000 and $30 million. Keystone Associates - is a unique company that specializes in the restructuring business debts and turnaround. With nearly 20 years experience, our professionals know how to deal with the most demanding creditors and reach the most advantageous settlements possible.