I wholeheartedly support this! I was so disappointed with the Imex Mexican War Americans. I wish a competent producer like Strelets would put out a set. Even one combo set of mounted and foot dragoons would be welcome.
I've had Mexican War games using Landwehr and cowboys as US infantry and Texas Rangers against Napoleonic French as Mexicans but it would be amazing to have at least one set of the real thing.
I would certainly buy them. Also various native Americans especially Apache, Comanche and Kiowa; all nations that have been largely ignored. If Strelets covered the Mexican wars they could produce some very colourful characters; including Mexicans in sombreros and regular Mexican Army.
Even though such a set would fit better with my 1/32 needs I would appreciate a set or two in 1/72 scale. I've used the Prussian Landwehr as US troops of the 1850s in overcoats - you do what you have to do. By the same token, the shorter jackets of the US uniform could probably be used as another nation's troops with a little imagination. I'd have to research it.
It is a gap that hasn't been adequately filled. I didn't even bother with the Imex set - their Alamo Mexicans' and Saxons' and Vikings' plastic totally turned me off their product.