The Sportello Amico at my local post office wasn’t as ‘friendly’ as I’d hoped; the clerk on duty told me the service is not set up to dispense residency histories, and that in any case he had never managed to extract a certificate of any nature from the system.
So there was nothing for it but to jump in the car and head into Rome, to the registry office of the municipio where I was last resident. There I queued for just under an hour, and in the end I got what I needed.
At that point, completing the application was child’s play. I did get it in by lunchtime, after all.
It now remains to be seen how long the prefecture takes to process the request. By law it has a maximum of 730 days to accept or reject my application, after which I can claim my entitlement before a judge. But I trust it will not come to that.