Hi all,
Thanks for the replies - we ended up with a similar solution to FroggEye.. though did all the work in the new app's web.config. Used Removes and Clears .. for example (note, these are incomplete snippets):
<assemblies>
<remove assembly="System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
<pages controlRenderingCompatibilityVersion="3.5" clientIDMode="AutoID">
<namespaces>
<clear/>
</namespaces>
</pages>
<httpModules>
<clear/>
</httpModules>
<httpHandlers>
<clear/>
</httpHandlers>
<system.webServer>
<modules runAllManagedModulesForAllRequests="true">
<remove name="RoleManager" />
<remove name="XHtmlModule" />
<remove name="CMSApplicationModule" />
<remove name="UrlRoutingModule" />
<remove name="Detector" />
<remove name="ErrorHandlerModule" />
</modules>
<handlers>
<remove name="MetaWeblogAPI" />
<remove name="ChartImageHandler" />
<remove name="UrlRoutingHandler" />
</handlers>
Everything is working nicely now.