I really am not too worried about rust and cracking of the stone at this point, but maybe I should be--I really don't know, maybe it is a point that you might care to expand on
I predrilled the stone with a masonary bit that was just the right size to accomodate the main body of the lags leaving the threads to dig into the stone--seemed to work real well--the stone is somewhat soft and forgiving--I had thought about wood plugs but I have had good luck using this system in the past, it might not work in all situations--wood plugs are good when you are working with real hard stone which might crack--or trying to secure items in a masonary joint which historically would be quite soft, and could fail.
My bearing are going to be white oak, which will suffice for this type of application. The majority of mill shafting of that period rotating at 100 to 125 rpm, used Oak bearings, with a sprinkling of metal babbeted bearings and at times Bronze, it sort of depended on their position in the shafting arrangement, the strain, such as the top bearings near the Turbine linkages, but then there is some deviations in this regard, for instance the shaft coming up from a 1865- 45hp water turbine is 4" in diameter rotating at a max speed of 125rpm is held in place with lignum vitae wood bearings, and the supporting bearing under the spinning runner (the working centre of the turbine)which is quite heavy--spins also on a wood lignum vitae bearing which uses only water as lubrication--now I know that we are straying away from the topic but I just wanted to let those that are looking in that wood bearings were used quite often as bearing material, remembering that overheating was something that needed to be payed attention to--I felt that in my case after pondering the course that I needed to support my rotating 80lb grinding stone oak wood would suffice, especially after you let it intentionally heat up to glass and char the surface in contact with the shaft (this is accomplished by running the shaft dry for a period of time)--a touch of oil periodically is all that should be needed from then on--
Now if there is a heating problem, my solution would be to lift the shaft dig out a little of the wood in the centre of the bottom bearing-- lower the shaft back down, within say a quarter of an inch of bottoming out and the pour in some heated babbet to form a babbet seat--not really a big deal--
I would like to true up the stone which is a bit uneven as it rotates, I have no experience in this regard and need some suggestions from you guys and gals