Good way to selectively merge XML docs?

[Jim Bancroft]

Hi folks,

I'm interested in merging two xml docs together. The documents use the same
structure, and in the case of similar nodes I'd like to keep the "newer"
one. I'll explain what I mean by that below.

For instance, if I have two docs like so:

<!--xmldoc1-->

<topnode>
<automobilepart>
<name>Radiator</name>
<version>4</version>
</automobilepart>
<automobilepart>
<name>Head Gasket</name>
<version>8</version>
</automobilepart>
</topnode>


<!--xmldoc2-->

<topnode>
<automobilepart>
<name>Radiator</name>
<version>6</version> <!--note newer version from above-->
</automobilepart>
<automobilepart>
<name>Spark Plug</name>
<version>4</version>
</automobilepart>
</topnode>

I'd like to create a document which is a combination of the two inputs, but
only has the "latest" version of a given autopart. In the example above, my
final document would contain a Head Gasket, a Spark Plug, and a Radiator,
whose "version" is 6. How might I tackle this? Could I do it with XSLT?
I'm using the MSXML3 parser to create the first two documents, if that helps
any.

TIA,

-Jim