Possibly a little smaller than you have in mind but I bought a Morgan lapel badge and ground off the fittings flush at the rear allowing it to be glued to any flat surface. In my case it was the centre of an M3W steering wheel.
Just checked and there is now a 6cm long version, click below.
![[Linked Image]](https://www.morgan-motor.co.uk/mmc/shop/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/i/m/img_1024_fixed-w1100.jpg)
