Regarding FR, you use to be able to get out of paying for your rating again if you had 500 737 NG hours but they have recently changed their minimums to:
At least 1,500 hours JAR 25 experience and 500 hours total time on the B737-300 to 900...
And regarding Fly Globe Span I spoke to them last week and presently they are only recruiting for the B757/767.
Korean Air via Rishworth require 300 on the NG and 1000 TT which I know you dont have but I think they would be a bit flexible with you since you have 500 on type....I know its a long way from home but its a job I guess..
Sorry to repeat the FR news seems me and Cabair wrote our posts at the same time...