What vehicle are these for? (ie, are they for my truck?)
Horns on ebay:

They are 1939 horns. 1939 was the only year to have gray accessory horns and they are complete right down to the firewall bracket.....a good deal for some one with a 1939
The accessory dual horns for a 1940-1941 truck were of the short sea-shell tpye and looked like the horns that have been used on passenger cars for many years.

I was going to send you a picture of the horns but lost your email address.

Almost identical to the accessory horns I have on my 38, a few minor differences (very minor) other than color. It's rare to see a set of horns that still have the pieces that clamp it to the "V" rod. Most are missing those pieces. A very good buy.

They did look like a pretty complete set. Thats why I was eyeing them greedily.

Chevgene, I would really like it if you sent a picture of the 41 horns if its not to much bother. My email address is kingisomerhotmail. I also a couple questions about the accessory horns: Were they higher or lower pitched than the standard? Did they necessitate the removal of the standard horn? Thanks!

They sounded like the 1940 and up passenger car horns with one high note and one low note, infact they were the same basic horn with mounting brackets that allowed them to be attached to the flat face of the firewall.
Would sound like any ordinary horn on a GM car (modern included)
The original horn was just a beep-beep horn and would have been removed.