So, I inherited this set of rapidograph pens. I love them! I've never used anything like them before. But, at the size I like to ink at, the #3 (.8 mm, green band) is just a little too large sometimes, and the #2 (.6 mm, red band) a little too small. I found out about the #2.5 (.7 mm, light blue band, not pictured below), which I'd really like to try out.
My question is, do I need to buy the entire pen, or can I just buy one of these replacement tips and put it in the body of one of pens i use infrequently? New to rapidographs and I know that they can be touchy and some iterations were/are discontinued; I don't want to accidentally buy something incompatible with my older set.