At the bottoms of the printed parts list it says. (*25mm specific parts have a 25 suffix) Do I need to print these parts even if I am using 24.5 and not 25mm
You need them all. If you are getting the STL file from thingiverse there are separate pages for the o.d. rail sizes. If you are printing for 25.4 you print everything from that thing page. If you are printing for 25mm o.d. rail size you print everything from that page Including the files that end with “_25mm.DXF” . If printing for 25.4 (1") o.d. you can pretty much ignore anything about the 25 suffix.
There’s 2 different item pages on thingiverse, one for 25,4mm and one for the 25mm version, choose the one you want and print every single thing in the Files Folder…easy !!!