You don't slap a forend on it has to be fitted to the draws etc. What is period correct. All furniture is correct when fitted correctly to a SMLE. These are battle rifles not Prima donnas. It is a pity yours has lost her original furniture. Just strip the paint off what you have if it worries you that much. I would also check to make sure that it has been fitted correctly then give it a good dose of BLOicon before refitting because this will tighten the fit.