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Henry Tardivat,

The Freiberger Trommel (drum) sextant I purchased on eBay a few years ago came with a Galilean 4x40 telescope.  The telescope optics are perfectly clear. They don't have the spots you mentioned, so this is definitely a defect. The smaller spots you describe may be due to dust.  Lens defects may also be due to moulds (or molds on this side of the Atlantic). In camera lenses these defects are called "fungus", which grows on lens coatings, but they usually look like filaments rather than a round spot, so the spot on your telescope are probably be due to something else.

As Noell Wilson pointed out, the front lens of this telescope may be removed.  You may notice two notches in the retaining ring that holds it in place. The two tips of a lens repair spanner wrench may be inserted into these notches to unscrew the ring. For obvious reasons, I am reluctant to try this on my telescope. If the defects are on the outer surfaces of the lens, it might be possible to remove them with lens cleaner. Fungus on lens coatings cannot be repaired.

As you have probably found out, it is possible to buy a replacement telescope from Freiberger Precision Mechanics (https://www.fpm.de) or from Navastro (https://navastro.fr), but their prices are higher than one would like.

Best, Rafael C.