Colchester Master 2500 - partial restoration of saddle- and cross-slide - 1

I was asked to partially restore a saddle and cross-slide for a Colchester Master 2500, just scraping in the matching surfaces between these plus replacing the screw/nut. It MUST be mentioned here that this is actually starting at the wrong end, ie near the "top" of a chain, but that is how "the task is given" to me. The CORRECT method would be to start with the bed, but this must be handled by a grinding shop. These hardened ways are also sometimes worn, though not as much as if the machine has so-called "soft ways", but with a lot of "hard use and little care" it is not unusual to see quite significant wear over a few decades .. PS! It is possible to calculate how much, or rather small deviation or inaccuracy on the workpiece you get at a given diameter over a given distance at a given "bed way error", but this is a separate chapter. In any case, a set of freshly ground bed ways forms a very good starting point for "working on" what is to sit on top, namely the headstock, saddle and tailstock. Since the bed ways and underside of the saddle have been worn and "adapted" to each other over the most used area, I leave it that way. This means you can either have the saddle so "tight" that it fits well when turning short lengths down at the chuck area, but that it "pinches" ie. it is not possible to crank the saddle upwards towards the tailstock, or that everything is loose enough so the saddle moves freely all the way and you rather reduce the cutting depth hence forces involved to avoid "induced vibrations" (chatter). I guess an alternative is to try to scrape the underside of the saddle to an "unworn area" of the bed ways e.g. up by the tailstock. Then the saddle and bed ways fit well up there.. but unfortunately normally resulting in either a less than optimal fit down by the headstock, maybe just touching at the far ends,) or binding completely (depending on how much you tighten the hold downs). Either way, not a good situation. PS! I am a mere taught amateur and I won't speculate what a pro could/would do, but I am pretty certain it would not be "best practice" if the saddle was to be fitted to like this..
Anyway, I have left the underside of the saddle alone and focused on alignment and removal of wear on the top mating surfaces, ie, the dovetail/gib section and the flats between the top side on the saddle and the underside of the cross-slide. Understandably, one of the important things to keep in mind is that it is rarely possible to add material after first having removed it, hence it is important to know just how much and where to remove by scraping to restore accuracy and functionality. This involves almost as much "detective work" as "machining", which has also been repeatedly pointed out by our mentor in the courses in the subject I have participated in.. (I cannot say this often enough, the best "investment" is to take a class! There are some to choose from and classes are run in many countries by several companies/persons.. as they once said "many ways to Rome"). It is important to find out "where the shoe presses" and "how hard", ie where is the wear and how much is this. This is logically reflected by how the machine has been used, ie which workpieces have been machined and to what extent it has been maintained. Ie. it is mainly a lack of lubrication that leads to wear on these surfaces, not the normal use within the machine's "correct" working range. In this case it was probably a wear of 5-8 hundredths at most. Slightly typical of the use of a large machine on small parts, the wear on the cross-slide screw and (double) nut was also quite significant over a small area.
PS! This has been covered on my other channel called "Haugjord's roterom", which is my way of serving our FB machinist group members with the content explained in Norwegian language.
The videos were more or less shot 2 times, one in Norwegian and then in what we bravely call English (haha)
Well enough talk .. let's start!