Why would you put the read-only resource in a EJB container?
The tomcat setup works just fine.
The resource has to be accessible to an application that is built as a pile of stateless session beans. They need to query this thing. Adding an extra protocol hop to another server is undesirable.
You dont provide that much background info so I give you a genric solution:
Wrap your service in a MBean.
Well, I have three questions about mbeans as an approach:
1) Can an MBean have JNI.
2) Can an MBean register a JNDI resource.
3) Can the results be relatively portable to IBM Websphere.
#2 is also asked in the other thread you referenced.