Hi Ian,

Thank you for contacting Mearto with your appraisal inquiry.
Asian silver has different qualities - sterling is 92.5% silver and 7.5% copper (and/or other alloys) - so hard to know for certain without testing/from a photo but it's niello (a black compound of sulfur with silver, lead, or copper, used for filling in engraved designs in silver or other metals) so I've valued this according to its similarities to other Southeast Asian cigarette cases.
For reference, you might look at this lot: https://www.liveauctioneers.com/item/52635993_four-southeast-asian-niello-silver-personal-items (LiveAuctioneers is a free website but you might need to register to see prices realized).

Based on the photos and information provided, and subject to examination, this is:

A vintage Southeast Asian niello silver cigarette case
made in Thailand, mid 20th Century
apparently unmarked, retailed at B. Sena Jewelers, Bankok, Singapore & Penang
The hinged case with cover decorated with engraved flying/dancing figure, the inside of the cover with engraved inscription
8 by 11 cm (3-1/8 by 4-1/3 inch)
CONDITION: appears to be in generally good condition; retains its original sleeve and box
PROVENANCE: inherited; purchased in Singapore in 1946
$40-60*
*represents a fair-market value for auction purposes; retail or asking price may vary.

Please let us know if you have additional items to appraise, and thank you again for using Mearto.