Hello. I have a 1970 Olds C/B ambulance which originally had a roof mounted siren. I believe this was most likely a Federal Q, so that is what I am looking to install. I have been searching online for sirens, and have found one for sale locally, but every one I find has a flat pedestal base. In all the pictures I have seen of a Q mounted to a C/B roof, the siren has an angled base to compensate for the curvature of the roof. How difficult is it going to be to find the correct base? So far, I have not been able to find one online. I am debating whether or not I should buy the Q that I found locally at a good price, then find the correct base later, or if I should keep searching for a siren that already has the base I need. Here is a photo I found online that shows what I am trying to do. Please note, this is not my car, but is a C/B with the same roof.