For some time I have toyed with the idea of fitting a Parker 51 nib to a Parker 21. The issue is, of course, that the price of a Parker 51 nib is very high so the transplant doesn't make much sense from a commercial point of view.
Nevertheless, when a very nice red Parker 21 with a damaged nib came into my possession I couldn't resist giving it a try. The 51 nib I used, dated for 1954, is quite unusual in that it has a broad point.
The pen, a Parker 21 Super, was fully disassembled, cleaned and checked before fitting the replacement nib:
As the 21 and 51 nibs are identical, apart from the material, the operation was a simple replacement. The 21 has an ink collector which is also almost identicsl to that found in the 51 so the ink flow was expected to be good and consistent. This proved to be the case, the pen writes with a wonderfully smooth, wettish line:
It is a really excellent writer, one of those pens that makes you look for things to write about simply for the pleasure of using it.