[Davew]

If we are talking about the (100)Mk5s converted to Mk IXs, then they were comon or universal,
If we are talking about the first production Mk IXs then they were non existant.
They are common in pictures of the conversion batch, but they are fairly low profile and people do not notice them.
No one noticed them in the first picture here.

Except they're not common, even in the conversions.
The link you posted has converted Vcs in it, but certainly the lead a/c doesn't have them, and possibly the second one doesn't either.
Most of the shots I've seen of 64 or 611 sqn a/c dont have them, and thats looking for them specifically.
Check out the shots on page 5 or 6 of this thread. They're conversions, and don't have the bulges at all.