I frame with "4 lines"

[carguychris]

Howdy all,

I have a question regarding late postwar "unimproved" (i.e. leaf mainspring) I frames. How common are I frames with the "4 lines" frame address ("MARCAS REGISTRADAS"...) rather than the simple "MADE IN U.S.A." marking?

I know that the leaf-mainspring I frame was superceded by the coil-mainspring Improved I frame very soon after the use of the 4-line marking began. I'm wondering if anyone knows the approximate timeframe and rough serial number range of these guns.

Thanks!

 

[H Richard]

If it's any help, I have a 38 Regulation Police, S/N 2786X shipped Dec. 1925 with a one line address, and a 22/32 Heavy Target S/N 44172X which shipped Sept. 1926. Both are leaf spring.