The files:

Roger Ceragioli's Refractor Construction Page
How to grind and polish a refractor lens and have it work well.

and

A Survey of Refractive Systems for Astronomical Telescopes

both by Roger Ceragioli,
have been removed from www.atmsite.org at the request of the author.

Roger wrote that he considers the information in the pages to be outdated. At this time, he does not have updated versions to share.