Something else to consider about the old timey vs modern pic.
The clothing style in the first pic is a the common style of dress for the period. You'd expect to see someone dressed as such whether they were walking about the house or going to market.
The second pic however has folks in camo. Now, yes, I'm fully aware that some folks wear camo all the time, but by and large that is not the common form of dress in the current time. Perhaps a pic of the folks in jeans/khakis and a sweater, or polo, or t-shirt along with their guns.
Not trying to make it all preppy on you, but if you wanted to get the point across that just like changes in clothing fashions, there are changes in gun fashions, then picking clothes that are mainstream in their fashion would help.
As for the message, perhaps something along the lines of:
"The times change a lot of things, but your Rights remain constant."