Hello JHM, thanks for that and for the link to the post on ME. I¡¯m glad I¡¯m not the only one to notice the issue.
I did find some burring at the bolt holes and a bit of dressing with a hand countersink has helped a little I think.
I¡¯m still going to make more of a gib type arrangement (when I get round to it :-) with oilon replacement strips of the same dimensions as the originals, and brass strips above them threaded to take grub screws to apply pressure to the oilon ones below.
I¡¯m keen to use a non-destructive solution, and certainly wouldn¡¯t be filing the saddle. My ham-fisted incompetence could make things considerably worse !
Cheers,
Peter