I would upgrade it. This is a hard time to sell guns. Lots out there and the prices are low. It would be cheaper to bring your current rifle up to snuff and sell off the unwanted parts verse selling it at a loss and buying a new gun.
Colt M16/AR15/ 1911 & Glock Armorer.
Certified Firearms Instructor & Urban Rifle Instructor.
Completed SWAT Entry Team and SWAT Sniper courses.
NRA Endowment Member
USPSA B class