There have been many threads in this Forum regarding such a project, Richard, especially since the revolution in TVs in the past 5 years. Usually it requires rebuilding the Beaver cabinetry, so though some owners with woodworking capabilities have done it themselves, most go to Bend, Oregon, and let one of the experts there tackle the job. Some of the original Beaver factory cabinetmakers are still there and no one else is as suited to the task.
You can click the "Search" tab at the top of this page to look for more discussions on TV retrofits, and many supply photos. You might, though, have to try several different word combinations in the Search field to glean a good assortment of relevant threads.
Joel