Both private Reserve and J. Hebin from Classic Nib work perfectly.
https://www.classicnib.com/supplies/inks-and-refills
Hi Roy
They certainly used to. as did watermans and diamines - but this new version which has been released is different. I am yet to find a cartridge with a shoulder which does fit.
I've just googled both of those names and they both have shoulders. I'm willing to bet they won't fit either
I've ordered a pack of Pelikan 4001's (picture attached) which I notice don't have the shoulder on them, so I'm hoping these will fit.
Here's the new version which sellers seemed to of stocked up on instead of the Jr Gent II's
RZ-FP51# Upgraded Jr. Gentleman I Fountain Pen kits
Chrome plating. Upgraded Jr. Gentleman I fountain pen kits. There are some improvements on the threads in centerband and nib, the pen will work better. The dia. of both tubes is increased by 0.6mm than the old series,that is ,now the tubes' size is 12.1*11.6*46.2mm and 10.4*9.9*53.4mm.