So, I was offered a chance to build a sample of this beastie if I was willing to prioritize it over the San Francisco and get it done.
...it was not a difficult choice.
The Montana class is simply huge. These monsters were ordered early in the war and promptly cancelled once someone in the Navy had the sense to do so. Still, they're magnificent looking ships.
Kit: My sample came with the prototype instructions and all three versions of main guns that Brandon offers. Had she been built, she would have been armed with the 16"/50 turrets. Nonetheless, BRM has decided to include the Navy's proposed (and built) 18" guns and some insane 20" bloody rail cannons.

Box. It's pretty.

Turret options. Sorry for the odd angle.

Included PE. I think there are plenty of 20mm, but you'll need more bofors for a full outfit. I planned on using Fine Mold guns, so I'm not worried. PE is excellent with the guns from Five Star Models. I'm unsure who makes the main fret but it's beautiful.

Superstructure.

More resin and the wood deck. I did want to note that the resin ship was designed with the wood in mind. The deck is recessed and will avoid the usual "sticker" look of the thicker wood piece.

Dry fit with the 18" guns. I'm still stuck between the 16" turrets and outfitting her with 18" guns. Engineering wise, I know for a fact that she's be waaaay overweight with the bigger turrets, but it looks so damn cool.

Montana and Iowa.

The kit also comes with PE doors and hatches which I strongly suggest using. Fit is good, though you'll want to sand the lowermost resin superstructure at the 3rd turret for perfect fit. It's a little long but should be easy to remedy. I haven't noticed any bubbles or warping.
I'll start work as soon as possible and work as the holidays permit. She'll be in the attractive Ms 22 unless I get adventurous and do her up in a dazzle. Pictures will be taken with all three turret configurations.