Hi Cruiser
I had pretty bad knocking, from the rear, all the original mounts were okay, but enough wear to give movement.
The centre one is the same one (EXH001), I havent fitted it yet, but had a good luck when it was on the ramps at the garage. Id recommend doing all of them with polybrushes, once you get underneath and see the difference its worth it, there is about a cm or so less play.
The middle one is easy, you can unbolt the metal bracket and slide the rubber mount off.
The rear two are more fiddly, you need to unbolt and take off the bracket, and angle grind a centre tube at the edges so it will come out, then replace with a nut and bolt.
Anyway, the long winded point im making is i think the most likely part to knock is the rear, although its good to replace the mid section one also.