A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Al Stewart
Date: 2023 Nov 13, 08:02 -0800
as Frank indicated, this is one of several "Tamaya-like" sextants produced in Japan during the 1970's-80's, probably by the "Tamaya Tokyo" factory, for other distributors.
I did own a similar full-sized OAKLET a year ago, but sold it; it had a 7x35 prism scope as well as the 12x20 inverting scope, also the half-width fully silvered horizon mirror (i.e. no transparent portion to the left of the silvered part) with full width Sun shade above.
I still have a couple other similar ones in hand.... an "International Nautical" and a "Simex Mariner". They both have 6-digit serial numbers, which tend to have alloy frames with bronze arcs, scope mounting adapters with groove located above the locking stud (i.e. not compatible with current acessories for Celestaire, C&P, Tamaya etc.) and the first two digits seem to correspond with the year of manufacture (i.e. 71xxxx = 1971). I noticed that other similar models with 4-digit serial numbers (e.g. SAURA, and some SIMEX from same period) have fully bronze cast frames, with groove on correct side of stud.