Same here on your opinion of Weatherby. They had several models of Accumarks just a couple years ago. I had one similar to yours in .270 Bee for many years liked the cartridge, rifle and stock not so much. They had a model with the AG Composites ADJ Chalk Branch model, and AG listed the MKV on their website a few years ago. I do not see it now. (I was going to replace mine, as I was in the same boat as you).It is definitely the model with the B&C stock, picked it up in 2020 with 40 rounds through her. TBH, I have never liked Weatherby rifles, love their cartridges, but I got this rifle so cheap I couldn't let someone else grab it for a steal. Just can't get comfortable with this stock…
I was told it is a Pro, alas, as far as I can tell looking at pictures, it is just a standard Accumark.
Cheers.
AG Adjustable Chalk Branch
www.agcomposites.com
You may be able to contact them and see if they still offer the MKV inlet.
PH