It is age-related. The earliest cars had chrome bezels on the air
vents and the gauges....then only on the gauges....then the chrome
disappeared altogether. Any of the usual Jaguar parts specialists
ought to be able to supply either type according to the age of your
particular model. Chromed gauges obviously look much better, but on
the other hand you should probably go for originality. I'm not too
worried as mine had the chrome from new ;-)>.

David Betts (davidb@motorsport.org.uk)
The Classic Car Gallery: http://www.ofoto.com/I.jsp?m=17830847103&n=398038677