You are looking for the 1983 and 1984 DX1 hood bird in silver. I think I've got a few NOS ones. Silver was only available in 84.
Just look for pictures of red 84 T/A's.

I think the decal works well with the 84 W62 cars, it matches the lower body stripes and ground effects. I think your Formula is pretty sleek looking, I dont know how well the horizontal stripes on the decal would match the cars lines.
I think there might be some on my message board. Let me find a link for you...