I would say keep it! My 1952 A-B-A NYC F-3's are the best operating engines I have. They pull most anything, run smooth, keep a steady speed and can throttle down to realistic speeds. I had the "B" unit for almost 20 years before I found the AA units that matched the condition I wanted, were good operators, and I could afford. I think if you let it go you will regret it. RUN IT! that's my advice
Don