Yes they have recoil lug cross bolts except for the really early ones. They went from none to a wooden one to the current steel one over the years. Early stocks had no cross bolts, no sling slots, and the slings were slung from the front hand guard band to the front of the mag via sling swivels. By the way if anyone ever sees a front hand guard band with a swivel I need one badly.

The damage I see on M91's, 91/30's and special Finnish rifles is split stocks in the tang area or forward where the wood separates the trigger hole and the mag well hole. They generally split lengthwise front to back. If the wood is in bad shape they will start to tilt the action upward at the muzzle end of the action. The Finns shimmed them upward in the rear to level the action somewhat in the stock. Now M39's are another thing and this is just a theory so keep that in mind when you read it. Ever notice how often the M39 stocks are split rearward in the tang area? I have found many and if you look at this real close you will find they barely sit on the recoil cross bolt and are not relieved enough for the tang to not hit the wood soundly before the recoil is absorbed by the cross bolt. If they shimmed the tang up enough and relieved the stock more in that area the cross bolt would do its job better and the stock would not split like a lot of them did. This is further made into a bad situation by the tang of the action sinking into the wood because there is no metal sleeve to keep it from doing that. I think the Finns might have realized this in certain instances and added the metal sleeve to keep the tang from sinking down and cracking the stock in the tang area. We have know for years the Finns shimmed the actions but in some instances I think we may have wrongly assumed they did it to float the barrel for better accuracy when maybe they did it to keep the stock from cracking. Like I said just a theory and I have no written record to base it on in anyway.

The Mosins with sleeves have only an occasional tight screw in the rear where the sleeve made it so tight a fit the it worked on the threads in the action or the screws themselves. Ever notice the screw holes in a Mosin stock compared to other rifles? They are huge and allow quite a bit of movement even when the screws are tight enough or over tight even. Adding that spacer cuts this room down quite a bit and cinches the action tightly to the magazine assembly and controls completely the angle and distance of the action and the magazine in the stock. If you cut the sleeve too long in the front or rear there is the distinct possibility of them being able to wobble upward and downward in the stock. Not a situation I would like to deal with for sure.

Room for lots of discussion here to say the least!  Best to All  Bill