Fixing a leaking Hydraulic Arm Cylinder on the Abandoned Excavator

The old Hitachi Digger has been leaking hydraulic oil from the arm ram end cap since I recovered it last year, leaking more than 1 litre every hour, it is time to replace the seals.
I'm finding it hard to get parts for such an old obsolete machine but the guys at FPD NZ www.fpd.co.nz/ went the extra mile and sent me a seal fit for a good price.