The MRC 99 action has slightly different inlet than the Model 70, recoil lug is different, bolt stop requires relief, and bolt handle comes back farther than the Model 70. Can be done but it will not look perfect.
Mcmillion would not reinlet the Edge LH SA Win 70 stock for the MRC for me had to do it myself.
The Tang was different also, shorter had to build up material on Edge stock. Glass stock easier to hide changes.
