Oops, in the first photo, the screw is in the center, partially blocked by the black rail.

I am not sure how similar they are, but when I did the carriage on my Royal KMM, the trickiest part was lining up the bearings/pinions when putting it back together. They have to be placed in just the right positions on the rails or the carriage will bind or grind.

Not on the 10. They, I believe, were right in front of two screws in the segment before I took off the carriage when it was centered, so i just put them there while I put it back on.

@ztyper I did not remove the arm, just loosen the screw a bit so the arm could move back and forth more easily.

One thing that wasn't touched on in the re-installation of the carriage:  placement of the 2 ball-bearings and their ring gears.  How I would start is to place them on the newly cleaned main track about 4" apart--putting the 4" space in the middle with the bearings on either side.  Place the carriage on (you'll have to weave it past the backspacer tab on the top to get it down onto the bearings. and be sure you place the carriage directly in the middle).  Carefully slide the carriage both left and right to see if either bearing goes close to the side.  If it does, you can install your hold down clips (the ones with the two bolts that install on the back of the carriage main track).  If not, increase or decrease the space between the bearings.  This will be trial and error here.  Eventually, you'll have it adjusted correctly.  But always be sure that the carriage contacts those bearings AT ALL TIMES.  Otherwise, they will roll out of adjustment.