This video has a comparison of three different duckbill mount/dismount heads being used in a manual tire changer.
Here are some links to accessories used in the video:
Hunter red duckbill:
https://www.amazon.com/Mount-Demount-Head-Hunter-Changers/dp/B00LC4MLPK
Black duckbill (corrected link 11/21/2020):
https://www.ebay.com/itm/Tire-Changer-Nylon-Mount-Demount-Duck-head-early-model-machines-Fits-Coats/190922259342
Stainless Steel Duck Head:
https://www.amazon.com/gp/product/B0797T938G/
Lucid Autowerks manual tire change upgrade kit:
https://www.ebay.com/str/lucidautowerks
Bead clamp tool:
https://www.ebay.com/i/183884462011
https://www.amazon.com/Changer-Clamp-Center-Universal-Hunter/dp/B06ZYTFRGB