From the way you pharased you question, I am guessing you are using the RDBMS adapter, you have created webservices, and you are trying to migrate from an old instance of iWay 5.5 Adapter Manager SP5 to a new instance of iWay 5.5 Service Manager SP1. To answer your question, yes, of course this has been tried. Now on to the specifics.
There are a variety of way to accomplish this portion of the migration. Here are some ideas:
1. Point the IBSP repository configuration at the same database you used in iAM SP5. This shared database approach can provide a low effort migration. It depends on a variety of things like database drivers, access, availability, etc.
2. Use the service provider migration utility provided in iSM SP1. This functionality is targeted at helping you accomplish what you are talking about.
3. Learn how to use the administrative web services that deal with targets. Thse services are typically available off of
http://yourhost:9000/admin.
Call support and open a case with all the details of what you are trying to do. We are listening and can help.