New bolts in - looks much better (and it seems to have stopped the leak, without putting any new sealant into the gap)
Had to take the timing chain off for access to do the the sealant, but it was impossible to get any sealant in as the gap could only be opened very slightly.
So then I had to time the engine up, something which I had not been looking forward to, but the worst bit was putting the tensioner back, hence the top tip with the cable tie, holding the tension on while I got the tensioner in place. Also put a cable tie around the crank pulley as the chain kept falling off.
All went smoothly until I dislodged the key (which locates the pulley) from the crank! Aaargh!