I have had two Slimline pens have trouble with the ink cartridges. Yes one was my carry pen! I purchased a set of Cross replacements (8514-2) but they extend out further from the nib then the originals. The original cartridge measured 4.56 inches and the replacement measures 4.58 inches. I know that is not much but is sure is noticeable. So my question is what is the recommended replacement.