Diamine inks are worth a look a look too, there's also converters for using bottled ink in cartridge pens. That said if the pen is gunked up inside that won't

Diamine inks are worth a look a look too, there's also converters for using bottled ink in cartridge pens. That said if the pen is gunked up inside that won't help, either flush it through or some pens like the Lamy Safari come apart with a little effort. For those in the UK, Cult Pens are a good online supplier, I'm sure the US will have some equally good outlets.