I wonder how Delf Bryce or Charles Winstead would have equiped theirselve for a rendeouvous with Platt and Matix.
I too am very intrigued by the lawmen of yesteryear and have done a lot of reading on the matter. Another guy that was tough as nails back then but not with the FBI was Frank Pape with the Chicago P.D. Robbery Squad. These guys did not hesitate. If you were a threat to them, they took the offensive and came at you like a wild predator.
It is hard to say what they would have equipped themselves with. However, being men of experience, I believe they would have taken some serious long guns with them. I think a guy like Bryce, after reading his biography, would have rushed Platt while he was getting out of the car and shot him at close range.