Ah, 1886. The year Coca Cola was invented, the first automobile was driven, and something was built in the Lower Haight.
It's been a long 125 years (well, circa), but the question remains: where'd we spot this sign?
Update 6/26: We have winners! Commenters Christine and Chuck both got it right — this sign is on the house at 391 Haight Street:
See you next weekend!