R&E Columbia/Improved Columbia lock

[Pschiffe]

For the first date, I did a search for 3/5/1889 (instead of 3/6) and a US classification code of 70/$ (locks) but none of the patents looked terribly relevant. I could certainly be wrong.
The second date probably refers to US patent 421,905 by Charles M. Burgess, assigned to Russell & Erwin, but is merely for a sheet metal latch case. It makes reference to an earlier patent 399,240 of March 12, 1889. This is also by Burgess and is a Russell & Erwin assignment.

Patent 399,240 is for a lock case, see link:
https://patents.google.com/patent/US399240
Charles M. Burgess, who had thirty one patents with the company (Russell & Erwin Mfg. Co.), received three major patents on sheet metal locks:

• #396,916 - January 29, 1889
  
• #399,239 - March 12, 1889
  
• #399,240 - March 12, 1889
  

Burgess also developed the forged steel bit key which reduced the cost of these bit keys and were stronger than those made from castings, patent #401,247 on April 9, 1889.*

*from Locks and Lockmakers of America, Rev. 3rd Edition, (c) 1997 by the late Thomas F. Hennessy, pg. 31.

Pete Schifferli