In the Vintage Space video episode Missions we Lost When Apollo was Cancelled, there is discussion of the Apollo Telescope and the Block 3 command module after about
The other thing to go was the Apollo Applications Program, which started life as the Apollo Extension Series.
By 1965 these distant goals were formally on NASA’s books under the Apollo Extension series, retaining the cache and potentially the funding levels of the Apollo program. And NASA had some pretty lofty goals for these initial missions, and it all hinged on using an upgraded spacecraft, namely the command module.
A Block 2 command module was the one that went to the Moon. The block 3 would be for the Apollo extension series and it would have some significant advances.
One of the main experiments under the Apollo Extension Series was to be the Apollo Telescope. This would be a dedicated solar observatory that astronauts could use to make observations of the Sun, from outside the Earth’s atmosphere.
The lunar module could also be used for other non-landing missions, around the Earth and around the Moon, and could start building the framework for a worldwide communications resource, and also just be used to fly packages of instruments.
There was also some talk of using the lunar module as the anchor point for that Apollo telescope. Basically the idea was to leverage the lunar module’s extremely reliable propulsion system into these longer missions
Question: How would the Apollo telescope have worked in the Apollo command module? Where would it be located and how would it be operated? I've added a number of possible interesting aspects to this in comments below, but because it's 50 years ago and there may be little information available, I'll leave this particular question with a bit of flexibility.
note: As mentioned in comments below (more than once), there was an "Apollo telescope" on Skylab, but that was a space station and laboratory. I'm asking here specifically about its installation in, and operation from the Apollo command module.