Does anyone know if the backrest bracket on my 2013 Ultra Classic will fit on a 2017 Ultra Limited? I'm trying to move it from my current bike to my hopefully next one.

 

For the driver or passenger? For the driver it should. The frame, rear fender and seat are the same. I have a 2017 seat on my '09 Streetglide and I use a drivers non adjustable backrest with it.
For the passenger I don't know. The 4 point docking hardware changed in 2014

 

2013 Ultra Classic
https://www.harley-davidson.com/stor...01-5259609a--1
2017 Ultra Limited
https://www.harley-davidson.com/stor...01-5259609a--1

I found this info on the Harley website, it is a great resource for checking parts interchangeability

 

driver's backrest

 

thanks