Sole proprietor with 2 business tax registration certificates - 2 tax returns?

Hi, I'm in Los Angeles, CA - the city gave me 2 separate Business Tax Registration Certificates's - one for my used vinyl record sales, and another for my music production work. Filing as individual/sole proprietor.

 

Does this mean I need to file 2 separate schedule C's? I use my home studio/office for both. I use the same car, same paypal account, bank account etc. 

 

Is there a way to file using both on one return? I've already started, so not sure how I would go back and separate everything.

 

Thanks