Saturday Starts Here had ceased to be by that stage - the programmes before Going Live that morning were linked by the continuity announcer, as I distinctly seeing the new-look programme slides in use that morning before the globe had been unveiled, as was the clock which introduced the unscheduled news summaries. As to what was used to introduce the other children's programmes that morning, I really cannot remember but presume it must have been the Children's BBC symbol of the time, as it certainly wasn't the globe, nor was it an in-vision presenter.
Yes, it was quite interesting - between 1987 and 1990, the pre-Going Live programmes (in the winter, at least) went out under the banner of Saturday Starts Here, with their own (pre-recorded) links, and after 1992 there was the Broom Cupboard on Saturday mornings, but between 1990 and 1992, uniquely at the time, the kids' shows were linked by normal out-of-vision BBC1 continuity, which seemed a bit of a step backwards. But it was just as well they did, as during the Gulf War that line-up was interrupted and rescheduled for several weeks.
Here's what the amended line-up was during the war - https://genome.ch.bbc.co.uk/schedules/bbcone/london/1991-03-09
- though, as I've mentioned before, by the time they'd started billing the news bulletins in the Radio Times, the war was over and they'd already stopped. That 8am news bulletin quite frequently overran, mind, and Eggs 'n' Baker would start nearer 8.20 some weeks, as seems to be the case that morning.
As you suggest, and as I remember too, that morning they used pretty much all the presentation elements of the new look - the clock, the slides, the menus (which were in the existing Winter 1991 style with the door, but with the new logo and font) and the OU logo, but not the globe which was kept until Going Live. Like you, I can't remember how they linked into the programmes themselves, but they must have used the CBBC ident.