Member List Go back to directory. Add to Address Book. Matthew L. McCahan Stahl Sheaffer Engineering, LLC 301 Science Park Road, Suite 333 State College PA 16803 work Work Phone: 814.733.4402work Cell Phone: 814.233.4200cell Work Fax: 814.233.0046workfax Work Email: mmccahan@sse-LLC.comINTERNET Categories: Members Updated 2 years ago.