I agree with Nitric. When you turn the photo upside-down, the keyhole-cover seems to say "W Mfg. Co."
You might be able to find a match-up for that distinctively-lettered logo at one of the antique lock collectors' websites. I tried the following site for you, but it doesn't seem to have late-1700s-through-mid-1800s locks. Antique Padlocks By David Heuermann