Seven grand? For a load of old flies?

My friend Neil Freeman offers a free valuation service at various fishing- tackle fairs. Almost without fail, he says, the stuff brought to him is worth less than the petrol expended to reach the venue.

Just because you have found an old rod or reel in the attic doesn't mean you can chuck away the Lottery tickets. Grandfather's prize rod generally turns out to be a battered old fibreglass monster best used for holding up runner beans.

If it's made from split cane, which many people think is the key to the tuck cupboard, it will have developed a curve like a longbow, the top will be broken, the cork handle nibbled by mice and some-one influenced by cubism will have painted it green.

Most stuff discovered in attics is out of sight for a very good reason. If grandad was such a cunning old fox, how come his reel is sharing a home in a battered suitcase with rusty bits of Meccano, a sock, six keys, and the world's ugliest lampshade? I have always been convinced the Antiques Roadshow is carefully scripted, designed to help geriatric Equity members. Until last week.

The unlikely setting was Ludlow racecourse, where a local auction house, Mullock Madeley, hold regular fishing sales. Thereare rarely any real surprises, and most serious business is done in the car park outside.

It's no good getting excited because you spot an old lure or unusual book in a box of scraps. I've learnt the hard way that covering a "sleeper" with less attractive items and hoping the pros don't spot it is like believing a Sunday train will run on time.

That's why I realised I was unlikely to buy Lot 390 cheaply. It was described as "an early 18th century leather-bound handwritten manuscript dated 1712. The writer, William Lister, has compiled a list of flies, then lists the feathers and materials required to tie each fly, together with page index to the rear. The bound volume totals 109 pages".

Though fly tying was documented as early as the 15th century, this diary listed some interesting dressings and patterns. Historically, it was an important and unknown work, though strictly one for anoraks.

"Bet that goes for hundreds," I thought. I know these things. I'm editor of Classic Angling. And I was hopelessly wrong. Within seconds, the bidding had topped £1,000. Two telephone bidders vied for the tattered old diary: £2,000, £3,000, £4,000. On it went. Finally, one gave up at £7,100.

Well, that sort of thing happens occasionally. But here's the twist. The seller had brought the book in just as John Mullock was putting his catalogue to press. "This could be quite valuable," Mullock said. "I'd like to research it further." But its owner didn't want to wait.

"Do you think we should put a reserve on it?" he queried. "What sort of figure were you thinking about?" Mullock asked. "I was thinking around £250," the chap said hopefully.

"Well, we could, but I suspect it will make a bit more than that," Mullock said kindly. "Trust me on this one." The rest is history.