Hello
Ok! In your example, you keep the bold header,
You erase the red style block, keep the blue placemark block, and the bold final lines.
I think the blue italic Look at section can be erased; personnaly, I have not this section.
Then, in every kml file (open with notepad, don't double-click for GE!), just copy its whole Placemark block, then paste in first file.
You'll have all placemark blocks following each other.
===============
<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://earth.google.com/kml/2.2">
<Document>
<name>Sudbury-Radar-Base.kml</name>
===================
<Style id="sn_ylw-pushpin_copy10">
<IconStyle>
<scale>1.1</scale>
<Icon>
<href>http://maps.google.com/mapfiles/kml/pushpin/ylw-pushpin.png</href>
</Icon>
<hotSpot x="20" y="2" xunits="pixels" yunits="pixels"/>
</IconStyle>
<LineStyle>
<color>ff0000ff</color>
</LineStyle>
<PolyStyle>
<color>19ffffff</color>
</PolyStyle>
</Style>
<StyleMap id="msn_ylw-pushpin_copy10">
<Pair>
<key>normal</key>
<styleUrl>#sn_ylw-pushpin_copy10</styleUrl>
</Pair>
<Pair>
<key>highlight</key>
<styleUrl>#sh_ylw-pushpin_copy10</styleUrl>
</Pair>
</StyleMap>
<Style id="sh_ylw-pushpin_copy10">
<IconStyle>
<scale>1.3</scale>
<Icon>
<href>http://maps.google.com/mapfiles/kml/pushpin/ylw-pushpin.png</href>
</Icon>
<hotSpot x="20" y="2" xunits="pixels" yunits="pixels"/>
</IconStyle>
<LineStyle>
<color>ff0000ff</color>
</LineStyle>
<PolyStyle>
<color>19ffffff</color>
</PolyStyle>
</Style>
===============================
<Placemark>
<name>Sudbury-Radar-Base</name>
<LookAt>
<longitude>-80.84384571358855</longitude>
<latitude>46.62658826565118</latitude>
<altitude>0</altitude>
<range>648.3005598507103</range>
<tilt>0</tilt>
<heading>5.842020081017863</heading>
<altitudeMode>relativeToGround</altitudeMode>
</LookAt><styleUrl>#msn_ylw-pushpin_copy10</styleUrl>
<Polygon>
<tessellate>1</tessellate>
<outerBoundaryIs>
<LinearRing>
<coordinates>
-80.84488455555501,46.62670986296985,0 -80.84523371757562,46.62651939189745,0 -80.84545886718516,46.62616600029333,0 -80.84553375200422,46.6257372486678,0 -80.84534700770561,46.625237839767,0 -80.844943149815,46.62503223214824,0 -80.84443552726272,46.62497775716971,0 -80.84390028534551,46.62505036710732,0 -80.84347402563473,46.62504674789928,0 -80.84305202082618,46.62509316117941,0 -80.84265250067239,46.6252093292012,0 -80.84223031887777,46.62537658054198,0 -80.84212557679749,46.62552977023082,0 -80.84208051280838,46.62582561521088,0 -80.8422592065576,46.62600330230579,0 -80.84235710095135,46.62613502894567,0 -80.84251194269363,46.62619196458932,0 -80.84251384259781,46.6263225391024,0 -80.84248003336555,46.62657969735967,0 -80.84248584217349,46.62685221747671,0 -80.84273363385096,46.62702509218014,0 -80.84323086018917,46.6270522913146,0 -80.84376870615191,46.62697917052391,0 -80.84418311102857,46.62690508380822,0 -80.84459628145436,46.62679287100748,0 -80.84488455555501,46.62670986296985,0 </coordinates>
</LinearRing>
</outerBoundaryIs>
</Polygon>
<description>Airport_Backgrounds_MaskClassMap_Excl udeAutoGen</description></Placemark>
================================
>>> insert Placemark block from each kml file
================================
</Document>
</kml>
==========
When opening this single file in FSX-KML, every line / poly will appear in the left-down part of window, and you may edit tags, ...
Hope it will work! Pierrot - FMEP