I've a collection of regulators for different cylinder fittings (including Campingaz), and some 'rattle' lightly, others don't! Not sure there is anything to be determined from either the presence or absence unless it's a change from one state to the other, which may indicate an internal issue!
If it's approaching 10 years old, it should be replaced as a routine anyway, and as said, if in doubt, for only a few pounds get a new one.
A day of all things motorhome and campervan. The show is held both in the main indoor arena and across the grounds. Catering, hot drinks and food options are available. Easy access to the site and free parking included. Win one of five pairs of day tickets