I finally got the siren installed. I had made two different ones that I didn't like and then two weeks ago I cam upon a new item on shapeways. Also found a new addition there of tow shackles for the Sherman so I bought both and got them set and installed. Now, she's done.
https://www.shapeways.com/product/85...li=marketplace
https://www.shapeways.com/product/RZ...118&li=ostatus