This post describes a series of Python scripts to convert FGDC XML metadata for WMS and WFS services to ISO 19139 service metadata via GeoNetwork's OGC harvest service. Here are the steps:

1. Extract WMS and WFS GetCapabilities URLs from FGDC XML metadata and write them to a file.
2. Create a GeoNetwork Harvest Node from extracted GetCapabilities URLs and let GeoNetwork's OGC WMS/WFS harvester create ISO 19139 metadata from GetCapabilities response. Note: the resulting ISO 19139 metadata is only as good as the one in the GetCapabilities response. In addition, GetCapabilities responses do not include all fields necessary for minimum ISO 19139 metadata.
3. Copy some FGDC metadata entries (Title, Abstract, etc.) to newly created ISO 19139 metadata.

Our goal is to have working WMS and WFS metadata records in our CSW catalog that can be used to add the described services to analytical software such as ESRI's C-SW Client for ArcGIS Desktop. Following are the reasons why I am currently choosing this convoluted process instead of a direct FGDC to ISO 19139 metadata conversion:

Files: 

MultipartPostHandler.py_.txt