Thank you for contacting Mearto with your appraisal inquiry.

It is a beautiful cocktail shaker. Such vintage and antique silver shakers are being offered at auction on a regular basis.
The silver shaker has a lovely design and today cocktails have again come into fashion which has made the price on bar tools like shakers, icebuckets etc increase.
The initials on the side of the shaker are probably from the previous owner. The design and shape is very classic and the decorative punching and the shape of the letters leads me to believe that it was made in the first part of the 1900s.
As you state yourself the silver mark is Columbian however I have not been able to find the silversmiths /manufacturers name. The silver quality is high with 900/1000 pure silver.
It need a bit of polishing but apart from that it appears to be in good condition based on the photographs.
The price depends on the weight - if it is heavy it is in the high end of the price range.

The estimate provided is for a well-advertised specialised online silver auction, where I believe the cocktail shaker has the best chance of realising its fullest potential. However, there is no measurement for the sentimental value you might attach to the Columbian shaker. Retail "asking prices" can be higher and vary.

Please let me know if you have any additional questions. I’m happy to help.
Thank you