There are lots of companies that make slip on pads--nice leather ones from Galco or Mulholland Bros. or J.W Hulme as examples...check with any of the big gun outlets, Natchez, Brownells, MidwayUSA etc for selection...
I got a couple from Galazan and a couple from Orvis--their labels, probably Galco but I finally had one made for me by a local saddle maker that laced up on the bottom, had a LimbSaver pad inside, came over the top of the butt and made a raised and padded cheek piece and has four loops for shells on the off side...
I also got him to make me a Cobra style sling with another ten shell loops and a slide on hand guard for the barrels that has a sleeve in it to friction fit a small tactical flashlight with an on/off switch on a wire on the side of the guard...All done in a nice basket weave with rolled borders...
This was for my eared 12 bore Rossi Coach Gun and I then got him to make additional sets for my wife's and daughter's 20 bore Rossi Coach Guns as well but with different designs...
I have heard that the Baikal are usually short stocked so the recoil pad just might be the correct fit for you...have your smith measure you and the stock...you can get thick or thin pads as well, KickEeze, Dead Mule, Pachmayr have some and Galazan has the English style hard rubber ones that work good on double rifles...