Which Lowell Observatory telescope is this? (used to draw Moon maps for the Apollo program)
That's the historic 24-inch Alvan Clark refractor.
It was installed in 1896 and restored in 2014-15.
Besides the moon mapping project, Percival Lowell used it to observe Mars, and Vesto Slipher used it for some of the first measurements of galaxy redshifts.
Its current mission is education; in mild weather the observatory lets visitors look through it.

Roger Vine's Scope Views has more photos and a detailed description.