Phillips were a large stationers in Oriol Street, Oxford.
As far as I'm aware, R. C. Phillips finished their days at the bottom of Oxford High Street (see here
) - at the site that's presently occupied by Pens Plus, although they may have started out somewhere else as I believe Reg Phillips setup the business shortly after the Second World War; interestingly enough, the last time I went into Pens Plus, they had a small cabinet of 'vintage' fountain pens amongst which was a black Swan Self-Filler with an R. C. Phillips nib (although in rather better condition than the one pictured below).
They may well have had a significant number of students as customers who expected a lot out of their pens - the most recent Phillips nib I picked up is in a monogrammed Swan SM100/60 which has obviously had a replacement clip, been well chewed, and has a chipped fill lever! The nib is lovely to write with, though, and is slightly flexible. This pen is in far from perfect condition, but is very characterful, and lovely to write with!
I don't have a proper camera with me at the moment, so this is slightly poor cameraphone quality, but here it is, with a quick and slightly scruffy writing sample!
These nibs were indeed largely made as replacements for customers, as far as I'm aware - I've heard in many cases for pens where original nibs were hard to come by. R. C. Phillips became the sole official repairer for Onoto, and I believe closed in 1978.
The man to talk to if you want to know more about these is Oxonian, I suspect. I know Eckiethump has a rather pretty Swan pen with one of these nibs in too, and may also be able to shed more light on this subject...
Edited by greenapogee, 28 May 2012 - 10:43.