To get it properly silk-screened won't be particularly cheap - I know of a supplier who can do it for £100 minimum charge, which I think that would qualify for.

The other option (which may be how it's been done by the oem) is to have the new legend laser/mechanically engraved/embossed to e.g. 0.25mm, then paint it in and wipe away any excess. This should be cheaper as anywhere with CNC mill or laser cutting facilities could do it.

Chris