Hello,
I'm having a similar issue. We are currently running NW 7.0 SP28. We have installed a new NW 7.4 environment. In NW 7.0, we had a system definition using template "Web application" which came from the com.sap.portal.howtos.webapp.par. I tried to recreate the system definition under NW 7.4 but there is no "Web Application" system template.
Where you able to resolve your issue?