There are two seal sizes used on the DJ forks. The forks produced through 2002 use 30mm fork seals. The ones produced in 2003 and later use 32mm fork seals. If you have a way to measure the outside diameter of the upper fork tubes, you will know which date range of fork you have. If all of the decals are still intact, Marzocchi often had the model year displayed right on the front of the lower legs, near the bottom.I have the serial number and a QR code but no clue how to determine the year, I'm sure it needs servicing and noticed different years have different seals and oil requirements so any help would be greatly appreciated!