Broadway Bench/Bed Runners

I don't know the proper term but the drawer like runners on one of the bench seats/bed of our Broadway need replacing. Spoke to A/S parts dept this morning and the lady found them in their catalogue, she initially told me they were £11.?? each + VAT + postage so I said I'll have a pair please.  She was totting it up  when she realised she had given me the wrong price, the proper price is £29.99 each + VAT + postage which is £76.97. I decided to look elsewhere. I've checked ebay and found some 40cm and 60cm ones but I need 50cm. So do anyone know where I can get some please?

Screwfix have some for £6.79 a pair.  They look like they will do the job. I am going through the same process but will probably fit something with a higher load rating, whether the extra cost is worth it is debatable though.

The Screwfix ones are 45mm deep and the ones in the Broadway are 17mm but I might buy them and see if they work. Thanks GROUNDHOG.

For other applications (i.e. drawers) I've always used Accuride runners.  They do several grades, depending on weight and other factors.  Available from them direct or from other suppliers.