Cat d6 9u

I have an old 9U D6 serial number 26347. I am told it is a 1957 model. She goes really well for her age but needs some TLC as the previous owner didnt use a grease gun all that much. If anyone has access to a parts book, I would love to know the part number for the steering clutch lever bushes as they are worn out in the old dear. I have been to the local CAT people and dont seem all that keen to assist me at this point so if I had the number of the part needed I would be very appreciative. Thanks, Pete