I have to say I ended up with a near complete set over the space of a few months simply by keeping my eyes open and having 10p or so spare in my pocket. To be honest, the novels themselves were often unreadable drivel based losely on the successful TV series. At the time, it wasn't a crime to produce merchandise that had little relevance to the brand it was part of. You only have to look at the Doctor Who annuals that World Distributors inflicted on kids each Christmas. But the best thing about the books were their often lurid titles - "The Stone Cold Dead in the Market Affair" is a classic.
Anyhow, this is a roundabout way of saying I was inspired to create some more 'Doctor Who' merchandise that has never been released. Last year I posted three covers for paperback books based on "The Men from UNIT" that bore more than a passing resemblance to those UNCLE novels. They were quite popular with my Facebook book friends and that nice Mark Gatiss fellow even tweeted me to say that he thought he had a set of them somewhere.
But I'm sure these little gems would be read and dog-eared by the end of the week.