Model 37 questions....|Winchester Shotguns|Forum|Winchester Collector

Hello.  For some reason this simple gun has greatly intrigued me the last few years, but I can’t seem to find out too much information about it.  What (I think) I know:  Please correct where I’m wrong.

“Pigtail” release lever was first year and maybe a bit of year two-1936 and 37.

Turned down “skinny” hammer was the first year or two-I ran across a 20 gauge that had this hammer but wasn’t pigtail the other day.

Turned down wide hammer was late 30’s until early 60s?

“Red Letter” from 1936 until 1948.

Turned up wide hammer was early 1960s?

Are there any other features on the timeline that I’ve missed?

I encountered a Turned up hammer 410 that had the “Winchester” script logo on the buttplate instead of the round logo.  Was this common among all Winchester arms of that era, or could it possibly been replaced?

Thanks in Advance!