Not quite sure when the cartoon went but the first part of The Crunch eventually moved to around 7.10am. The cartoons returned for a brief period in 1997 when it was rebranded as Alien Alarm and essentially took the first half hour of the show.
In fact the cartoon lasted rather longer than I remembered, because looking at the Radio Times here, they were still showing Sonic The Hedgehog at 7.10 in the autumn of 1994. I think they must have phased it out around that time, though, now you had Power Rangers on GMTV and CBBC on BBC2. Initially it was because they had to appeal to all audiences, of course. Then during the school holidays The Crunch would move to 8.45 with another cartoon during it. That said, I remember around that time This Morning used to show cartoons during the school holidays.
Everyone forgets the big attraction in the early days was The Banana Splits, it featured in the trailers and everything, but it was clearly the kind of thing you enjoy seeing again once and then it totally loses its novelty. I do remember in the very first week Zig and Zag weren't on the Thursday because they did Master Blaster during the Crunch slot instead, but seemingly Zig and Zag were so popular they immediately changed it so they were on every day, with Master Blaster moving to its own slot.
I would suggest that Vaughan does just about overtake Roslin as the longest serving presenter, as you say by a few weeks, though I'm sure Vaughan had more time off.