Signature: Gruen Guild (some with "Factory T")
Maker/Supplier: Factory T
Cleves proposed intro date: 1920
Details: 10.5L Guild sisters to the 9.75L "Gruen W. Co" Calibers 145-6-7-8-9. Cal 266 shown as 15J variant in 1926 parts sup B, making 267 the 17j variant.
Differentiation (vs. cals 145-9): I noted 5 ways in my post on cals 145-9. Visually easiest is, look for no hole near edge of plate, between balance & smallest finger bridge.
