Previous nonunion met. stress fx- orif 6 mths ago. still some pain and swelling, recent xrays, scans say fracture margins still apparent. not healed?

Stop delaying..: More of a possibly delayed union in the making, but hard to tell. The pain and swelling are signs of some residual instability of the reduced site. These hard to heal fractures can be real stinkers at times. Consult with surgeon for his opinion. If not convinced, or if you have concerns, then get a second opinion. There is absolutely nothing wrong doing that.