Waterman 52 1/2
This chased, black hard rubber lever filler started life around 1920s with a ring-top cap, but by the time I found it at a flea market, the cap was cracked beyond repair. Luckily, fivestarpens.com had a nice replacement cap that fit perfectly, with an identical, if somewhat crisper pattern in the chasing.
This is a small pen, too small for my hand for daily use, although it’s tempting because of the easily-controllable flex in the nib. I’ve a very soft spot in my heart for old Watermans, but that’s a club with easy entrance requirements.