COLUMN: Oliver Chisholm was a racing commentator at the Racing Post for more than 25 years until he took a gamble on playing with toys. Since then, he has gone on to become one of the south west's leading experts on all things Dinky, Matchbox and Corgi.

So if you are lucky enough to have a clockwork Mickey Mouse your grandad bought you in 1939, or an entire collection of still unwrapped Barbie dolls going back to the '60s, let Oliver speculate on their worth.

Take a close look at the festive turkey this year. Somewhere under the parson's nose there is sure to be an endorsement from JK Rowling.

Christmas is being taken over by Harry Potter. In fact the entire country has gone crackers his picture is probably on them as well.

Spilling out of your Harry Potter stocking or piled under your Harry Potter tree there is a mountain of merchandise featuring the schoolboy magician.

And, on past records, it is guaranteed that some of it will be sought by collectors in 20 years or so. That is the usual time span for mature adults to start yearning to recapture their childhood.

No-one can predict what will prove the best investment from a range as huge as the Harry Potter collection but, gazing into my crystal ball, I see Hornby's Hogwarts Express in a mist of steam.

The Hornby company has staged a wonderful recovery from the brink with some superb models and Hogwarts Express falls into two lucrative collecting fields, memorabilia and railway.

A signed first edition of Harry Potter and the Philosophers Stone was sold in Salisbury recently for £13,000. I cannot guarantee the same return on the train set but mint and boxed it should certainly outspeed inflation.

Back in the '60s every child put Thunderbirds on the top of his or her Christmas list. The originals from that series have long since graduated from car-boot to auction room.

I recently sold a simple Fairylite doll of Parker to an Australian collector for well over £100, while Lady Penelope's Dinky model of FAB1 could make more than twice as much.

A decade later Star Wars was the number one gift wish and in the '80s along came Transformers. Rare examples in good condition are making three figures.

It is arguable whether Teletubbies or Bob the Builder will stand the test of time but there is every likelihood that Harry has that durability factor.