Back end of Jan 94 - Apr 94:
Mon/Fri: Danny Baker, Tue - Thu: Chris Evans.
Apr 94 - Sep 94:
Mon/Fri: Mark Little, Tue - Thu: Chris Evans.
Oct 94 - Feb 95:
Mon-Wed: Paul Ross, Thu - Fri: Mark Little.
Feb 95 - Apr 95:
Mon - Tue: Paul Ross, Wed - Fri: Mark Little.
Apr 95 - Jun 95:
Mon-Wed: Richard Orford, Thu - Fri: Mark Little.
Jun 95 - Jul 95:
Mon - Tue: Keith Chegwin, Wed - Fri: Mark Little.
Jul 95 - Jun 96:
Mon - Fri: Mark Little. (Keith Chegwin did a lot of cover for Mark from Jul - Nov 95 due to Mark being at the Edinburgh Festival and on a comedy tour.)
...then Mark was axed, Keith stepped in and Rick Adams took over in Sep 96 for that rubbish revamp.
Yeah, that's all correct. Mark Little first appeared at the beginning of 1994 standing in for Evans for a week and then appeared on a couple of occasions before becoming a regular presenter. There were a couple of occasions in the first few months, when Danny Baker was presenting on Mondays and Fridays, where Evans and Little would sometimes be on together and Little would do The Crunch and a couple of other features (though as Evans points out in his book, The Crunch was usually pre-recorded anyway, and presumably Little came in the house for continuity reasons).
When Paul Ross took over he was only supposed to be a temporary measure, I remember it being billed as such in the papers at the time, while they found someone to take over full time. One reason why he went down to two days a week in February 1995 was because he was getting in the tabloids regarding his relationships. Richard Orford was supposed to be the full time replacement but they still had to keep Mark Little on for contractual reasons, I think. At that point Little more or less assumed that was the end of him, hence why he decided to do the Edinburgh Festival and a stand-up tour. But Orford was seemingly unsuccessful because within two months he'd been swapped for Cheggers, and then Little was on five days a week. All of this came out of the blue, Little was on one Monday in July and said he was going to be doing it all week now, but not to worry because Cheggers would be there when he was away - and indeed because of Edinburgh and his tour, in fact by the end of the year Cheggers had actually been on more than Little had.
The two big mistakes they made with The Big Breakfast when Evans left were not appointing a full-time replacement for him, and not changing the format enough. As it says in Morning Glory, for nearly eighteen months, it was simply impossible to answer the question "Who presents The Big Breakfast?", which in a show that revolved so much on the personalities of its presenters was totally ridiculous. Then if they didn't revamp it when Evans left, they absolutely should have when Gaby left, in 1995 and 1996 it was just a desperate retread of former glories.
Then of course when they finally got a full-time presenting team in Little and Ball, the two hated each other.