I started by readng a bit of this wonderful article: http://authors.aspalliance.com/anjum/ASPMigration.aspx
Based on the information in that article I've rewritten the default.asp page from
And renamed the file from default.asp to default.aspx.
One thing I noticed is that the inclusion of aspcompat="true" led me to believe that it would be needed in order to process some of the older ASP code in these pages, but even without everything is okay so far. (leaving it nonetheless)
I've skipped the xml.asp tranformation for now, attempting to get the easier solutions in hand, first.
At the top of the open.asp page which I renamed open.ascx making it a user control I added the following
And where I used to have the leftBar.asp included I replaced
At the top of the open.asp (now open.ascx) I used to have the following
This gave me the error
Server Error in '/' Application.
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Compilation Error
Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.
Compiler Error Message: BC30800: Method arguments must be enclosed in parentheses.
Upon removing the offending code, which turned out to be
all was well, but this is something I will have to return to, in order to find out exactly what ramifications it has on the caching of the pages.