Welcome to the Strelets Forum. Please feel free to discuss any aspect of 1/72 scale plastic figures, not simply Strelets. If you have any questions about our products then we will answer them here.
Shellhole Scenics have infantry, artillery and cavalry sets for several units. Early War Miniatures do some as well. All in metal. https://shellholescenics.co.uk/product-category/mexican-revolution/ https://earlywarminiatures.com/product-category/ww1-1914-1918/ww1-1914-1918-mexican-revolutionary-period/
It appears both have solved the problem of casting a sombrero by supplying separate heads.
I am not connected to either manufacturer other than being a sporadic customer. Regards, Pa