Pensioners on mystery tours, transatlantic visitors, designers, photographers and stage managers regularly drop in just to see the artefacts, says Evan Jones, the project's director. Probably some are still there, happily building model bridges with blocks and ropes, trying on Victorian costumes, playing African or Australian musical instruments or just browsing through the still uncatalogued collections of photographs. The temptations are infinite.
The Education Resource Service, legacy of the legendary empire created by Sir Alec Clegg (the West Riding's pioneering chief education officer from 1945 until his retirement 20 years ago) has been reorganised, updated, pruned of the more expensive works of art and made available to schools throughout the North of England.
It is an impressive affair with 25,000 objects arranged in themed sets from Africa to World War Two via Artworks, Farming, India and Transport and including a complete gamelan orchestra. Some of the resources, especially in the Greek and Roman pottery collection, are genuinely ancient. Others, like the magnificent Roman armour shiny gold and silver helmet and breastplate, goat leather desert boots are brand new.
Fortunately, says Mr Jones, there are still pockets of real craftsmanship dotted around the country leather and woodworkers, engineers and builders, creative seamstresses who kit out today's Roundheads and Cavaliers, museums or theatres and who can, on demand, recreate designs from any historical period you care to name. The ERS draws on expertise from all of these as well as museums, art galleries, universities and training colleges.
Thus one junior school head was able to don full centurion's kit and, helmet flashing, spear and shield at the ready, boots striking sparks from the stone, to march about on Hadrian's Wall, recreating the magic of the past for his awestruck class. Sir Alec would have approved.
It is ironic that all this is housed in one of the West Riding's middle schools created under his leadership. Currently the familiar green "boxed resources" are stored in the old gym and the theatre, but plans are in hand to build a new display gallery where customers can see exactly what they are getting, collect them on trolleys and then take them away through the check-outs.
For the most part, however, schools use the Resource Directory to order from a distance. Every item in the collection has been photographed and listed in the catalogue. Thus "Coal - E106", shows a boiler suit, a pair of miner's boots, safety signs, fossils, helmets, a model mine and a water-colour painting. Schools can hire on a one-off basis or put together a programme for the term. The hire of a single unit, typically including a number of large and small artefacts and a collection of ready-to-hang pictures, works out at Pounds 45 for four weeks or Pounds 2.50 a day, perhaps for an exhibition or school play.
Increasingly, says Peter Berry, the business manager, teachers choose a complete year's programme, minimising costs by combining delivery and collection. Each school is asked to appoint its own ERS co-ordinator. Given that the delivery vehicle is allowed just 15 minutes to pick up and put down, that everything has to be checked and any damage recorded, it helps if one named person is in charge.
Some schools prefer to pick and mix a treasure chest of their own choice or even to hire a complete set of costumes. "This is definitely not playtime clothing," says Berry, "but costumes which have been made as close to the original as possible, introducing laces, tiny buttons, hooks and eyes, something which is a real eye-opener for the children of the zip and velcro generation."
Since the introduction of technology into the curriculum, the houses and building section has achieved star status with delights like "build your own drainage system" and "housebuilding" as well as the more traditional "historic houses".
Backstage in the workshops, model bridges - "hinged", "rainbow", "arched" or "wobbly" - all designed with the help of Professor Francis Evans of Sheffield Hallam University, are in production. The thoughtful tree sculptures and their tiny maquettes (trial models) contributed by Hazel Brocklehurst, are awaiting collection along with the latest extraordinary addition to the Fairground Life collection. Life-sized painted "gallopers" and merry-go-round panels, a model showman's caravan and the pi ce de resistance, something that gives away all the secrets of the trade.
On the outside it is a neat, uninspiring silver long-loader lorry - a box on multiple axles. Parked in the fairground, its sides unfold to form a circular platform, the driver's cab is disconnected to leave a neat, boxed drive unit behind, the little cars or horses are slotted into place and it becomes a magic roundabout. It is a metaphor for the whole Crigglestone undertaking. Nothing very remarkable on the outside - pure magic inside.
And as if all this was not enough there are also "familiarisation days" for teachers approaching some new area of the curriculum like World War Two. "They can come here, spend a day in the 'US Army camp' complete with tents, jeeps, campfire food and all the sounds and smells of the real thing." It is, says Evan Jones, guaranteed to give an injection of realism to the curriculum that they will never forget.
Education Resource Service, The Resource Village, Crigglestone, near Wakefield, West Yorkshire WF4 3LB. Tel: 0924 240999, fax 0924 254425