I have been a CET private owner for about 8 years, I had 2 from the first releases which were a bit rough, I had to swap a few engines and steering boxes to build 2 from about 6 in a friendly military breakers yard, that is how I learnt about how they work, plus purchasing all the manuals from Vintage Military Manuals and then spending hours studying them.
I sold one to a collector in the Northeast a few years ago, then in late 2012 I had the opportunity to swap the other one for one of the very tidy ones in the big batch currently being released at Withams which also had been sold as scrap as it was a non runner.
The latest ones have all had the swim levers, splash boards, and the drive props to the Dowty water jets removed, however I was able to save these from my old one before it was scrapped.
As far as I am aware I have the only CET crane attachment in the UK, I know of one other in the USA. Over the years I have managed to collect most of the CES, some of it coming from other members of this forum when they have purchased CVRT equipment in the Withams tenders which it has been mixed with.
Due to the knowledge I have gained over the period of owning one I have been able to help out other CET owners in fault finding on them and on the odd occasion help out with spares.
As for the rocket propelled anchor, this seems to be the most illusive piece of CES, I have all the drawings to make one but have never been able to actually find an original one.
With regards to reliability in service I have heard some horror stories, after Gulf War 1 questions were asked in the house of commons regarding the fact that they were the most unreliable vehicle deployed in theatre.
On visiting the REME Museum reserve collection in Bordon on one occasion I was introduced to some regular REME guys as"the bloke who owns a CRARV trailer" to which they all fell about laughing and reeling off stories of how many times they had towed in CETs.
As regards to spares, just buy 2 they are that cheap at the moment !