Good Morning Bjorn,
I would concur with Gray, I have a S7 long bed bought new c1976 with power cross feed, recently I had to strip down the apron for servicing of the half nut [operation became stiff ] Even though my machine has been in daily use for all these year there was no appreciable wear on any of the components/bushes etc in the apron. I would not worry at all — as Gray says lubricate and forget it for many years.
Incidentally I used to use a "sticky" oil Shell Toner R41 for the gears and lead screw – now run out of this and its no longer available so now use chain saw chain oil which is "sticky" and tends not to run off the gears and lead screw.
John