Thanks a lot for your help, @Vero!
I have a _long_ list of quotes that I want randomly inserted, so I wanted to keep them in the text file (which also makes maintenance easier) rather than a list field in Alfred.
I have it working now. I had run into issues with my first clipboard paste - my signature - not coming through and only my second paste - the quote - turning up twice. Turns out I needed to insert a little pause (slow, slow, slow is the way to go) in order to make it work: