Reusing and editing recordmaps in studio

I have a fixed width complex recordmap that is an older version of a file format. I am trying to retool it to fit the latest version. The old recordmap has almost 500 entries on it and the new version has a few more fields added along with changes to some field lengths. Adding a new field adds it at the end of the recordmap and moving it from field 490 to field 139 is a painful process. Is there an easier way of doing this?

I have tried editing the recordmap by going to studio and moving the fields to the correct location. I recompiled it and it changed the Storage Default and it looks like it numbered the new fields accordingly. However, this change did not reflect in the recordmap when viewed in the Management portal.