I'd say u did have great success with your first box of nickels. That buffalo looks like its in amazing MS condition. Seems like a lot of great buffalo finds lately in amazing high grade condition. Btw, its kinda strange that I had very similar success with my last box of nickels too - I found a '36 buffalo and two silver nickels also. But my buffalo wasn't anywhere near as nice as the one u found. That was my best nickel box in some time.
Glad u had such great success starting out. Hope u have continued success. HH!