Treets "Treets melt in your mouth, not in your hand !"
Aidan's right, they had a coating like Minstrels.
Mint Cracknel This is one they really should bring back.
I blame it for my life long addiction to anything minty.
Marathon Bar 490 BC - the Greeks defeated the Persian army at the battle of Snickers - doesn't sound right does it?
BTW - the 8 inches of braided caramel & chocolate was (& still is, albeit a lot smaller) called Curly Wurly in the UK. It was banned in Ireland until 1979 - don't ask me why.
VCRs Our first VCR was a betamax (can't remember the manufacturer). It was the size of a suitcase & the timer record was a 3-way switch. You could only record for 30 minutes, 60 minutes or to the end of the tape.
Split knee trousers If you mean they were one colour above the knee & another below it, I had a pair of corduroy flares, top half black & bottom half purple.
Computacar It was actually Computacar - I had the white one & never managed to get my own cards to work well enough to get through the traffic cones.
AFAIK it came out in 1970.
East European children's programmes The one with the tree & the prince/bear was "The Singing, Ringing Tree" (Brilliantly spoofed in "The Fast Show")
I think the Flashing Blade was either French or Italian & I agree about the theme tune.