I normally oil my target rifles with Tru-oil and then use stock sheen to give a satin finish, I only use enough oil to fill the grain and protect the wood to prevent it getting too glossy, shiny target rifles don't work as they give too much reflection and will do nothing for a steady grip. If you want a tougher finish use stock wax after the oil but again rub over with stock conditioner/sheen to give a satin finish..looks and works great. Avoid getting the oil on the stippled grip area's, These I normally leave other than a clean with a stiff brush and some alcohol, (meths or similar)
Walnut stain works really well and diluted will produce a nice natural colour, one thing I did on an Original 75 was to stain and then rub back the normal contact areas a little to give a naturally used patina before oiling, came up really nicely. Be careful if thinking of staining the stippled areas a different shade as the stain will "bleed" a little into the surrounding wood before it dries. These areas will normally accept more stain than the surrounding wood so will generally come up a little darker anyway without looking unnatural.