Looking at a 257b with 820 hours with one new track and one I would rate at 50%. Current owner purchased on iron planet two years ago for 18,500. He has run it privately for about 150 hours and wants 18,500. Engine door has yellow writing that says Cat engine replacement @ 616 hours. A phone message back from my diesel mechanic said stay away from 257b, problems? My question is this, does anyone know what other problems may persist? I understand the engine was most likely replaced due to the oil feeder tube casuing engine failure.