Ultimately, the contract of sale is between retailer and consumer. So if your purchase fails, you can return it for refund or replacement according to your statutory rights. even if it is more than 24 months since the retailer took delivery. Any retailer who tells you otherwise is pulling a fast one. and a retailer who can conduct repairs could attempt the repair themselves at their own cost.
Retailers have no such protections unfortunately. but most manufacturers and suppliers offer good terms for replacing faulty goods. Heljan have always had a 2-year limit, its a risk we must face on "New old stock"
The cynic in me believes that this may be to try and influence retailers to clear old stock, to get new stuff in.
In reality, it will result in smaller orders, with less stock in storerooms and more "Just in time" ordering, to keep the shelf-life of stock as long as possible.
With respect to repairs, Warranty repairs and refunds will be subject to this time limit, but it is worth noting, that whilst it is good customer service for Hornby to accept direct repairs, the contract does not exist between Hornby and the consumer to honour the warranty directly, as it is effectively between Hornby and the retailer. (Unless Hornby retailed the item of course)
What are Hornby to do if the model cannot be repaired? how much did the customer pay? how do they account for refunds?
These issues are easily resolved with the retailer (or they should be). this step takes away the confusion of introducing third parties or breaking links in the supply chain.