How to change REST service URIs?

11.6.3 linux REST, Classic Appserver, tomcat 7

I've got a situation where each REST service of a project was deployed as an individual war file, with the resulting URI looking like so:

http://hostname/servicename/rest/servicename/method/etc.

This URI structure can't easily be changed. 

What I'm looking to do is automate the current REST service deploy process using restgen / restman. These tools allow me to specify a list of services that go in a war file like so: service1:service2:service3:service4. If I do this with a project SomeProject, and then use that project name to construct the war file name (ie SomeProject.war), the URIs after deployment would look like this:

http://hostname/SomeProject/rest/servicename1/method/etc.

http://hostname/SomeProject/rest/servicename2/method/etc.

http://hostname/SomeProject/rest/servicename3/method/etc.

This URI structure would break many things if it was implemented. 

One option I could pursue would be to generate a .war file for each service and give that war file the target service's name. This would preserve the existing URI structure on deploy at the cost of extra overhead to maintain and deploy each .war file.

What I would prefer to do would be to alter a mapping somewhere in tomcat that would redirect requests from the current URI structure to the new all-services-in-one-project/warfile structure. 

ie 

http://hostname/servicename1/rest/servicename1/method/etc.

would be redirected to 

http://hostname/SomeProject/rest/servicename1/method/etc.

Tomcat has a 'rewrite' valve that looks like it'd do what I want:

https://tomcat.apache.org/tomcat-8.0-doc/rewrite.html

Has anyone else successfully accomplished this goal?