mcjnic!...
Sorry I didn't see this thread till now as I would have been able to save you a little time, although you DID in fact do the right thing here! The problem with your drum was that it had NO SNARE BEDS. NONE... NADA... ZERO. That is why your snares were buzzing. As soon as I looked at your pics I knew, as I have seen this from Slingerland many times!! Whomever built this drum or worked on the shell at Slingerland completely forgot to cut in the beds. Possibly built on a Friday??!! LOL!! Anyway...
All the snares can do is just lay there... flat ... as the throw/strainer had no way to pull the snares "up and in" to the bearing edge, as again, the bearing edge was flat... no beds. The result of that is always... snare buzz... and there is no way to eliminate that without cutting in some snare beds, which is exactly what you did. Excellent! Think for a moment on how the snare bed functions: With the bed cut in, it allows the snares to be pulled "up and into" the bearing edge, creating the proper contact with the bottom resonant head. The result is as you found: Round, warm, crisp. Fact is, Slingerland blew this one... and many more that I have seen over the years too. Regardless, you made the adjustments, and got the drum playing/sounding the way it was intended!
I do have a 1968 Slingerland 51/2X14 Buddy Rich Artist snare drum in WMP, and it DOES have snare beds cut in. Perhaps this drum was built on a Wednesday!! :-)
Tommyp