look on the right side of the mast outer channel between the tilt cylinder rod end mount and the base of the mast. there is a mast arrangement number there, it should look something like '3B25C'.
that may not be the exact number so just see what is stamped there and come back here and let us know what is stamped there. We need the mast arrangement number before we can get you the right part number for the packing kit or at least let you know if there is a kit available or not. I see some info that says no parts available on some of the arrangement numbers and the complete cylinder may need to be replaced instead.