[Wavytone]

It's a fake.

There were some genuine "Ye olde brass tellyscopie" that did actually work for those who wanted a loungeroom ornament that were made as recently as the 1980s and 1990's - even Bintel had one once I recall.

There have also been a few fairly good replicas made in the U.K. over the years, too.

But there is much worse. From the 1980s onwards there has been a thriving industry in India making knockoffs of antique instruments - telescoepes, theodolites and levels, sextants and so-on. These inferior copies turn up in antique shops quite regularly and dealers frequently try to pass them off as the real thing.

They also turn up on Alibaba in job lots of 10 off at crazy prices.

They are frequently branded with the names of the classic makers (eg Cooke etc) and look passable to those who don't know any better - my guess is they are based on photos of the real thing at Greenwich and so-on.

But if you look closely you find several things may be amiss:

- no original box (usually mahogany) with set of eyepieces, Herschel wedge and other bits & bobs,

- the manufacturers nameplate or engraving does not match the known style of the real thing, often with a spelling mistake or incorrect address,

- the year of manufacture is wrong (doesn't correlate with the history of the company),

- telltale signs of creating a fake patina that give away that the brass isn't old - and often it's not even solid brass but some sort of cheap plate on tin if you look closely at an edge with a magnifier;

- the wooden tripod and box will be in a condition that only real age can produce,

- the objective is often a singlet lens, or wrong focal length for the tube it's in, and while the eyepiece has some glass in it, it doesn't function as one,

- no provenance tracing it back to the original maker.

For the money they are asking this would have to be fully documented with every sale from its manufacturer and verified.