The chains got new pins and bushings and the sprockets were available through Berco . I found a recipe that said the front idlers were from a TD7 . Bottom rolls we had built up by a machine shop on an automatic welder . Seals for the bottom rolls matched up to I believe a caterpillar part number . The top rolls were the only thing unavailable, at the time . I build those up myself with a mug welder . If I’m not mistaken, the top roll bearing and seal were matched up at our local Napa with some aftermarket parts. That machine had to have over 10,000 hours on it easily . Cleared many acres of farm land