I purchased a Quadrafire 4300 back in 1998 and have never used it. After all these years I've now decided to actually install the thing. I know the new 4300's have an efficiency rating of 80% and am just wondering what the rating was for the 4300 back in 1998. Basically, I'm trying to determine if I would just be better off buying a new, more efficient stove. Any thoughts appreciated.