I have an excellant national match rear sight set, includes NM/2A sight base, NM windage knob (1/2 moa) and NM hooded aperature (1/2moa for elevation by rotating sight hood. .0520 aperature). Has only slight finish wear on aperature hood. This is all you need for the rear sight, you re-use your elevation knob and pinion and rear sight spring cover.
Asking $100 shipped or best reasonable offer, I would also trade straight up for a good complete AR bolt/carrier group ready to drop in and use. TRADE PENDING