I can provide a bit more info on Les Pretend - John Sherwood died in 2003 (don't know when exactly). From when I started reading the Beano in 2002, Les was in it most weeks until around July/August '03, when he started to appear less, and Sherwood strips continued to appear until December, by which time he was appearing less regularly (the final regular Sherwood strip appeared in issue 3205, 20th December 2003, apart from one that appeared six months later, that had obviously been stockpiled).
He then disappeared for a few weeks, then returned around February/March '04 in a couple of episodes drawn by Steve Bright, before Trevor Metcalfe took over. Trevor drew two runs of strips I think, in summer 2004 and spring 2005, with an odd one in October '04, before he disappeared again after issue 3283 (20th June 2005). I don't know why Trevor stopped drawing him then - it wasn't because DCT dropped him, that was later. I have a feeling it might have been because he took over Billy Whizz at the same time.
Les's strip wasn't seen again until issue 3365, dated 27th January 2007 as a John Sherwood reprint. This was when the Beano started to regularly use reprints, and this run lasted up to issue 3375 (the same one where Fred's Bed and Riot Squad started), dated 7th April 2007. Another reprint appeared in September before Laura's one-off strip in Beano issue 3402, 13th October '07. After that, he was next seen in issue 3444 (9th August 2008), as a reprint, since when Les strips have frequently appeared in the comic. I know in the Beano Top 100 he was listed 18th, but he's overtaken Calamity James, and by now Pansy Potter as well, placing him about 16th (though he may have passed Baby-Face Finlayson as well, depends on how many times he's appeared). He'd made 649 appearances as of July 2008.
A bit a long read I know, but I find this stuff interesting.
