Is this an STC?
http://www.faa.gov/certification/aircraft/stc1.htm
Do you mean Milner?
http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgSTC.nsf/0/353A74446AF5AC7185256CC2000C5F89?OpenDocument&Highlight=cowl%20flap
STC Number:
SA4-80
This certificate issued to:
Milner's Aircraft and Engine Service, Inc.
STC Holder's Address:
8165 First Ave. South
Seattle WA 98101
United States
Description of the Type Design Change:
Cowl flap linkage system.
Application Date:
Status:
Issued,
Responsible Office:
ANM-100S Seattle Aircraft Certification Office Tel: (425) 917-6400
TC Number -- Make -- Model:
A-669 -- McDonnell Douglas Corporation -- DC-3 Series
=====================
"If the mail you sent was returned "undeliverable" and there is no phone listing for the holder, please contact the issuing FAA office. Supplemental type certificates are approved and issued through FAA aircraft certification offices (ACOs) which serve the geographic area of the supplemental type certificate owner's residence."
Hope that helps!
BK