I have a 2001 2619. I can tell you what has failed in ours which may give you a guide as to what to look for. Ours has been heavily used so that may be more important than age.
- Side-mounted AC. Failed and had to replace. Now need to replace drain pan
- Add lift kift to allow addition of 15" wheels and higher capacity tires
- Propane line from oven control to burner wore through due to vibration
- Latching pins on front stone guard lift arms wore out
- Many issues due to screws backing out due to vibration, especially under dinette table
- Dust guard on propane regulator crumbled from age, had to replace
- Check valve in city water fitting failed, replaced fitting
- Water pump head failed, replaced head
- Tabs on interior curtains pulled out
- Faucets need new washers to stop leaks