Horn ID? - Pics

[burner31]

Can anyone ID this horn?
Looking for year, what it came on, and a guesstimate on a price.
There are no marking on this, other then "adjust"near the center rear screw.
I paid $65 total on e-bay.
It all metal, it works, it's loud, but may need some oil, I get the A-UUUU, but barely a GAAA.
My current cheap horn sounds like a sick/weak goat.

 

[fordman67]

Though I have nothing to add from a technical aspect that is identical to the horn on my. 25.

 

[burner31]

Update:
Cleaned it up (inside), oiled it and installed it.
Sounds great, loud with the perfect Aaa-ugaa sound.