This is the lens you require, you will also need a c-mount adapter and a selection of extension tubes/rings
http://www.ebay.com.au/itm/like/Schneider-Componon-S-50mm-f2-8-enlarging-lens-excellent-condition-/231697621349The projectors will no longer work as projectors after the modification, they will only be good for scanning.
So noted.
The link you provided show this: “This page does not exist. Please continue to shop on the eBay.com.au home page.” Any other link ?