https://doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=596201
https://doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=195452

I found 2 more images from Toby Barclay's sleeving tutorial. Note the sleeve extends the full length of the chamber

[Linked Image from photos.smugmug.com]

'SLEEVED' on the breech

[Linked Image from photos.smugmug.com]

In contrast the monobloc used by almost every Italian maker, and Browning, today; and different from the Beretta 1903 patent

[Linked Image from photos.smugmug.com]

Oops

[Linked Image from photos.smugmug.com]