I consider myself a competent engineer and in my experience it is better to let the professionals do a job like this. Yes the seals can ware and harden but the metal parts can also ware and new seals will not overcome this.
I use these people
https://www.kileyclinton.com/ to do steering racks and they come back as good as new and a 12 months warranty. I have had racks from other suppliers that leak in a few weeks of days and apparently a lot of companies dont even leak check them and when you consider over 1000psi is involved.
Fitting the rack and finding it leaks is a complete ball ache in my view let alone getting the tracking done again.