I saw the garage this morning. A couple of spark plugs had been crushed and sharded at the bottom. They are 90% sure one of the valves has come loose and fallen into the pistons, and are fairly certain the engine is screwed.
They are saying they have to quote 14 hours to replace it as they have to do things by the Renault 'book' times. They have said that if this takes less time they will of course charge less. Their top mechanic hasn't done a 182 engine, but apparently they do a lot of work for Renault changing engines in some Renault concept car, I can't remember the details. This is quoted as taking 20 hours and their top mechanic can do it in 10, so hopefully the £800 labour quote will be more like £400-500 for the 182.
This of course is without the extra cost for regassing the air con (£65+VAT), new cam/aux kit (£150?), and new water pump (£25?).
I think I'm looking at about £600-1,000 all in with them. I trust them so know they will do a good job. They will obviously guarantee their work, but not the engine I provide.
Engine wise I am still hoping to find one for sub £500.
I just want the car back on the road.