Heay, yeah!! I was just thinking about this programme the other day. I used to love the theme tune
"Ba dum dum dum dum dum dum dum dum-ba dum-bum ba-da dum, BOING!!"
I'm pretty sure it was Helen Spiers, rather than Spears. Whichever, I think she looked a bit like Su Ingle, who used to present a wildlife programme with Terry Nutkins (this was before The Really Wild Show)or possibly Derek Griffiths.
Jonathan Cohen used to do music for all kinds of children's progs back then - I think he composed the music for the last series of Playschool (before they replaced it with the diabolical Playbus). As to what he might be doing now, Gawd only knows. I doubt he's a mudcatter, so we'll probably never know.