Komatsu PC400-5: Cheap parts? What to watch for on this model?

Just got an old PC400-5 with around 4000 hrs on it. First excavator purchase. Mostly going to be used on the ranch for putting in some new roads, laying some irrigation pipe and digging some ponds.

Need some various parts like replacing a couple of the grease lines (they apparently broke and were bypassed with direct zerks but now very inconvenient to reach the zerks). Can I use some sort of generic grease tubes, or do I have to pay big dealer prices, or are there good sites to buy...

Komatsu PC400-5: Cheap parts? What to watch for on this model?

Komatsu PC400-5: Cheap parts? What to watch for on this model?