Have just done a complete service of a SID XC 2001 that I got for my next kids bike project. I don't think this thing has ever had a service. The damper oil looked like this:

...the stanchions are nicely scratched:

...someone's had one or more hamfisted attempts to remove the crown race:

...and the stanchions are showing some wear around the upper bushings:

Nevertheless, after a service they feel pretty good and should do the job on a kids bike.
Components weights:
- CSU (crown steerer unit) - 647g;

- Lowers (with v-brake bosses) - 500g;

- Damping rod (right side) - 71g;

- Air piston rod - 37g;

- Negative spring - 21g;

- Air caps (2) - 24g;

- Air dust caps (2) - 4g;

- oil - 110ml (100ml damping and 5ml + 5ml splash lube) - about 100g.
Total weight
Total weight with 210mm steerer, v-brake bosses, all fluids and star nut: 1441g.
Tuning - suspension
Standard weight damping oil is 15W. For lighter riders 10W or 5W can be used. For a 35kg rider I am using 5W oil.