repairing a steering rack and installing new seals requires 2 major parts.
1 - proper tooling
2 - proper mental health and knowledge. (no naswaar, paan, lack of sleep)
the shiny thingie you see in the picture is the rack itself, if its scratched up then Im pretty sure the bulkhead in the housing is bad too, With a proper equipped shop they can redo the rack and bulkhead to take up the slack and then would need undersized seals to complete the job.
The pinion valve body requires hydraulic assembly lube which is similar to the item used when rebuilding automatic gearboxes. Grease of any kind should never even be close to the assembly bench.
Whenever you install a rebuilt rack it is a mandatory requirement to blow out the reservoir container inlet screen, to do this you need unmount it and blow ATF with assistance of air pressure backwards, you might need to use a solvent (but be sure to rinse the item with clean ATF/PSF/hydraulic oil) to make sure there is no solvent content in there anymore.
The screen traps thick sediment that can destroy the pump vanes and also damage the rack itself.
here in USA - power steering line filters are sold that are installed somewhere in the return line to trap any debris, they are fully serviceable too. Some rebuilders will not give a warranty of their rebuilt rack or pump if you do not use an external filter.