I've searched everywhere on the Apple retail site but there doesn't seem to be anywhere on their website that lets you view the stock levels of new ipads in individual Apple stores. Does anyone know if this facility exists or have you got to ring the store concerned to find the answer.

Many thanks.

you would need to speak to the store in question

https://www.apple.com/uk/retail/ipad/

You can reserve one online for collection in your chosen Apple Retail Store. If a model is not in stock in the chosen store, it will show as being unavailable.

If they ever did there would be plenty of web sites totalising Apple sales region by region.