Got mine yesterday, delivered by a mobile service technician, who said he'd bought a bunch of them along, in case there was a fitting issue. So I surmise the underlying cause of the delay is a bad batch which didn't fit properly - which, with this locking design, would mean the lock might not close properly, and there would be a subsequent risk that the hook could come loose in use. Or, in other words, "a disaster waiting to happen"!
Only took 'em three months...
Only took 'em three months...