OK, this is just because I hate having to redo perfectly useful existing work!

I have a UL built in CC HTML Editor, which is long and has many linked items in it. *It took a long time to put together.*

I am laying out the same list, now in RSD. Is there any way I can avoid having to go through and rebuild all those linked items by hand? Can I salvage the existing pre-built list items but just *get them to work with the UL settings I have already created in RSD*...?

Basically, must I redo all that work...?

I can't think of an easier way to add html than using the html element. You paste all the code from your old site.
Of course, if you have some special styling for the list, I'd think it best to create a 'custom.css' and place the styles there. And if the linked-to items are bits and pices on other (or the same) pages in the site, you need to add images, videos, etc to the resources, and otheways check that the paths are set in accordance with your new system.