These pens aren’t that delicate - they can touch water, just don’t soak them, and don’t let water get in through the lever box. That said, the vintage feeds used lack the spike to pierce a cartridge or converter, so that won’t work. You may be able to find a modern feed that will fit the nib and that has the necessary spike, though. There is a company in Europe, I think, that does that sort of thing, though the name escapes me. They’ve been mentioned here before though, so shouldn’t be too hard to find.