Master Padlock Lion Logo Key Dates Wanted

[Retro00064]

...in 1977 discontinued....

Interesting information. Based on what I have seen, I had thought the lion keys were replaced circa the late 1960s or possibly early 1970s with the key design shown below (note that the back of the key remained unchanged) (the round-bow keys with the Master name in "wild" lettering, used on the #3, #4, #77 and (long discontinued) #88 padlocks, were also replaced with a round-bow version of this key). What did you get that info from?

[...] Sometime in the 1960's the material was changed to brass....

Might the switch from nickel-silver to brass have actually occurred in the 1950s? I've seen N.O.S. Master "Secret Service" padlocks with brass keys with boxes of the style used from circa the second half of the 1940s to about 1964 with the older "World's Leading Padlock Manufacturers" slogan on the back, instead of "World's Largest Padlock Manufacturers", which was used on later examples of that box style. Looking on eBay, I see that Master was apparently using the latter slogan in magazine ads as early as 1955 (that may or may not mean that Master started replacing the slogan on the boxes that early, but I'd think it wouldn't have been too long after).

As an aside, interestingly, I have a couple of circa later 1930s to circa mid 1940s N.O.S. Master #3 padlocks (one with a "USN" marking on the bottom) as well as a N.O.S. #77 from about the same era (of the original design with the walking lion portrait, not the lion head logo) with brass keys (even though the #77's box states it has nickel-silver keys). I also have a #4 with the "USN" marking with its original box from around that era that has nickel-silver keys. What's up with that? Did WWII have something to do with it?

That walking lion is in fact a US trademark. It was applied for on October 1, 1931 and issued March 29, 1932 as number 292,893. You can probably find it online at the US patent and trademark office web site.
BBE.

Thanks for that. Here is the registration certificate for that trademark (this is one of those trademarks where the registration date and a scan of the certificate appear to be the only data on the mark in the USPTO website, so you can't find it using the TESS search system, but you can find it with the TSDR search). The certificate says it was filed on October 31, by the way.

Master also re-registered the trademark decades later as #979,377, filed April 12, 1973, registered February 26, 1974, and cancelled September 23, 1980.