Would like an instruction manual for a WesternField M 842 rifle with a WesternField 4X15 scope?

I believe your rifle was made for Montgomery Ward as the Mossberg Mdl 346K. Made from ABOUT 1958-1971, and there was never an "instruction manual". There was an envelope attached to the trigger guard, that held one folded (and very basic) instruction PAGE. The link below will take you to that page.