[Alex van de Wetering]

The hub of that flail is really banged up. Perhaps enough to have put it out of balance? Some of the control arms on the right side for the Flail also appear to be broken, missing or disconnected? Again, I wonder if all is connected to having hit a mine.

the primary reason Avalon was put out of action may well be due to mines.

I agree; I think before being put out of action, Avalon was already crippled from mine damage. I think the flail jammed and the drive shaft on the right snapped. Today half of the drive shaft is hanging from the right hand side, but in the early days the other end of the shaft was also still present. Maybe the mine damage and it loosing a track meant it was a sitting duck for any German weapons.

I think I have seen tall boxes like the one on the left side of the Crab, on both sides of a Crab on display at Borden. They might be Chalk Boxes used to mark either side of the trail being cleared.

I actually think the left hand side box on Avalon in the early museum days was an ex-wading stack used as a box for spare chain, which I think I have seen on more Crabs, especially during the fighting in Normandy. It seems not all crabs had the chalk boxes or the later arrow system.
The long box seen in some pictures is the standard British tool box seen on Sherman V's. I think Avalon might have had two as I seem to see a crushed one on the rear of the tank as well. I think the other one might have been welded on the left hand hull side, behind the other box, as there are still some welds in that location today. The right hand hull side also shows some welds.....these are closer spaced; I think this might have been where the standard British turret box might have been located when it was hit by multiple rounds. I couldn't find any remains (angle iron) or welded on the rear of the turret that would indicate the box to ever been fitted there.

The turret is always in the same position. I cannot imagine at least one person in all these years not having tried to move it. Any indications it still works and it is just being kept ‘as found’, or is it jammed?

Exactly my thought! I presume it's jammed. Ten years ago the museum gave me permission to enter the tank, but I didn't try to turn the turret!

I would not focus on the terrain you see in the pictures.

Well David did got me thinking! All sources say the tank was moved from the battlefield to the museum, but I agree with David that the look of the terrain in some of the early pictures is somewhat similar to what the resting place of the tank would have looked like after some exploding mines! Than again....I guess moving around a Crab without a right hand track in soft sand, will give a similar look.