Brand
Charles-Félicien Tissot and his son Charles-Émile founded Tissot in Le Locle in 1853, and the business grew on exports, with Russia among its most important markets. Tissot has always liked trying new things. It made the first series-produced antimagnetic watch around 1930, the fiberglass Sideral in 1969, the mostly plastic Astrolon in 1971 and the stone-cased RockWatch in 1985. Around 1930 it joined Omega to form SSIH, with Lemania supplying chronograph movements, so a vintage Tissot often shares parts and engineering with an Omega of the same years. Inside that group Omega took the luxury end and Tissot the middle, and vintage Tissots still sell for less than their Omega cousins. The ones to hunt are the 1950s Navigator world-timer, the PR 516 skin diver, the Lemania-powered chronographs and the fiberglass Sideral.
5 references we cover.

Tissot · Visodate
Dressref Visodate Seastar
$240–$390 typical ask
150 on eBay

Tissot · PR 516
Diveref PR 516 (refs. 44544, 44622)
$260–$370 typical ask
52 on eBay

Tissot · T12
Chronographref T12
$1,525–$1,900 typical ask
10 on eBay

Tissot · Sideral
Diveref Sideral / Sideral S
$270–$525 typical ask
49 on eBay

Tissot · Navigator
Pilot and fieldref Navigator
$775–$2,300 typical ask
32 on eBay