Hello mate, Those are indeed my cabs. Judging by the horn cutout that is just visible, that is an MX350. Made for 10" speakers. All the horns in the MX range of cabs are built in as an integral part of the cab. The horns, of course, are wood. Hence the sound and the weight which every body seems to complain about.
As I said, the horns are built in, they are not separate horns. Build the horns with the box like I did. Once you've done that, you're on your way with a fiber glass mould, and then the world is your Lobster as they say.