Importing eBay 800+ listings... Help!

We are new to Garage Sale, and are in the process of uploading 800+ listings from our eBay store. Is there a way to switch all of the items from a like category to an identical listing format? For example, 300 of the listings are records. I have created a template to duplicate with all pertinent info when I list new records, can I apply something like that to existing imported listings? For example: I’m using the PRO Sidebar Store design… I have some basic info I want on all of my record listings that are input through the inspector (about us, payments, returns, buy more & save, and shipping). Would I have to type these categories into every single record listing that I imported from eBay, or is there a way to transfer the info to many listings at a time in the scenario?

Not sure if I got you correctly, but you can select several listing while holding down the shift key and edit all the information in the inspector for all selected listings.