Revised #Sitecore7 SwitchMasterToWeb.config for Content Delivery to one available at http://sdn.sitecore.net/Reference/Sitecore%207/Scaling%20Guide.aspx . Some additional configuration was required to remove Master index configuration.

SwitchMasterToWeb-V7.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/" xmlns:set="http://www.sitecore.net/xmlconfig/set/">
	<sitecore>
		<sites>
			<site name="shell" set:content="web" />
			<site name="modules_shell" set:content="web" />
			<site name="testing">
				<patch:delete />
			</site>
		</sites>
		<IDTable>
			<param connectionStringName="master" set:connectionStringName="web" />
		</IDTable>
		<databases>
			<database id="master">
				<patch:delete />
			</database>
		</databases>
		<search>
			<configuration>
				<indexes>
					<index>
						<locations>
							<master>
								<patch:delete />
							</master>
						</locations>
					</index>
				</indexes>
			</configuration>
		</search>
		<scheduling>
			<agent type="Sitecore.Tasks.CleanupFDAObsoleteMediaData">
				<databases hint="raw:AddDatabase">
					<database name="master">
						<patch:delete />
					</database>
				</databases>
			</agent>
			<agent type="Sitecore.Tasks.DatabaseAgent">
				<patch:delete />
			</agent>
			<agent type="Sitecore.Tasks.DatabaseAgent">
				<patch:delete />
			</agent>
			<agent type="Sitecore.Tasks.DatabaseAgent" method="Run" interval="00:10:00">
				<param desc="database">core</param>
				<param desc="schedule root">/sitecore/system/tasks/schedules</param>
				<LogActivity>true</LogActivity>
			</agent>
			<!-- START: Addition to Sitecore SwitchMasterToWeb.config - Remove optimisation of sitecore_master_index -->
			<agent type="Sitecore.ContentSearch.Tasks.Optimize" method="Run" interval="01:00:00" patch:source="Sitecore.ContentSearch.config">
				<indexes hint="list">
					<patch:delete />
				</indexes>
			</agent>
			<!-- END: Addition to Sitecore SwitchMasterToWeb.config - Remove optimisation of sitecore_master_index -->
		</scheduling>
		<contentSearch>
			<!-- START: Addition to Sitecore SwitchMasterToWeb.config - Remove core and master index configuration -->
			<configuration type="Sitecore.ContentSearch.LuceneProvider.LuceneSearchConfiguration, Sitecore.ContentSearch.LuceneProvider">
				<indexes hint="list:AddIndex">
					<index id="sitecore_core_index" type="Sitecore.ContentSearch.LuceneProvider.LuceneIndex, Sitecore.ContentSearch.LuceneProvider">
						<patch:delete />
					</index>
					<index id="sitecore_master_index" type="Sitecore.ContentSearch.LuceneProvider.LuceneIndex, Sitecore.ContentSearch.LuceneProvider">
						<patch:delete />
					</index>
					<index id="britishlibrary_contentdelivery_master_index" patch:source="Sitecore.ContentSearch.Lucene.Index.Web.config" type="Sitecore.ContentSearch.LuceneProvider.SwitchOnRebuildLuceneIndex, Sitecore.ContentSearch.LuceneProvider">
						<patch:delete />
					</index>
				</indexes>
			</configuration>
			<!-- END: Addition to Sitecore SwitchMasterToWeb.config - Remove core and master index configuration -->
			<!-- START: Addition to Sitecore SwitchMasterToWeb.config - Remove syncMaster and intervalAsyncMaster strategies -->
			<indexUpdateStrategies>
				<syncMaster type="Sitecore.ContentSearch.Maintenance.Strategies.SynchronousStrategy, Sitecore.ContentSearch">
					<patch:delete />
				</syncMaster>
				<intervalAsyncMaster type="Sitecore.ContentSearch.Maintenance.Strategies.IntervalAsynchronousStrategy, Sitecore.ContentSearch">
					<patch:delete />
				</intervalAsyncMaster>
			</indexUpdateStrategies>
			<!-- END: Addition to Sitecore SwitchMasterToWeb.config - Remove syncMaster and intervalAsyncMaster strategies -->
		</contentSearch>
	</sitecore>
</configuration>