Bumping this with some good news to help anyone who may also have the Parker 21/51 pencil laying around... • The Parker's lead equates to the modern .9 refills. Because the sticks the Parker came with (from the '50s) are noticeably harder than I'm used to and so make a lighter imprint, I've replaced them with Pentel's HB .9 from Walmart for about a buck and a half. I wouldn't mind finding a softer/darker B or 2B but they seem hard to come by, so I'll live with the standard HB. • The white vinyl eraser from the cheap Bic disposables (a pack of which is also dirt cheap) fits dead perfect into the Parker's inner barrel, without any trimming. Couldn't fit better if it was made for it. So if you come across a Parker pencil, use without fear! Between this and my several bottles of good ol' blue/black Quink, I now enjoy my matched 21 set daily and couldn't be happier with them.
