Your second request for marriage certificate for:

"David W. McGovern and Deborah P (don't know maiden name) and don't know 
when they got married.  They are in their 60's, so maybe around the late 60' 
and up.  Both McGoverns are going into a nursing home and medicare needs 
their marriage license."

A copy of the complete marriage license is online for:

David William McGovern, b. 20 Mar 1947, living at the time of this marriage 
in South Burlington, Chittenden, VT.  Marrying Deborah Gail Howard (Phelps - 
her maiden name, assume there is a previous marriage to Mr. Howard), living 
same town.  Her birth:  11 Apr 1951.  Married 15 Jun 1978 in Burlington, 
Chittenden, VT.  Vermont Vital Stats should be able to send you a copy.

Best luck