Those Firestones came out in 1948 and haven't changed much... There was an earlier version that was even worse, very squared off, almost like a 5.60-16 bias ply car tire. They are suitable (barely) for HD Big Twins, Indian flatties, Drifters (either size), Vulcan 800 Classic (doesn't handle worth a crap no matter what tires are on it), etc...
Dunlop, Avon, Michelin, Metzeler, Kenda, Shinko, Duro, German made starts with an H and I can't spell it past there. Not enough money in the world to make me run Bridgestone/Firestone or I.R.C. brand tires on anything. I'll run JC Whitney Chinese cheapies before I junk up a bike with those 3 brands... I'd run 40 year old Goodyears or Carlisles instead of the I.R.C. junk that ships standard on one of my bikes...
All of the big names make modern construction "retro" treads. Check the weather and speed ratings, and if you ride on chip seal or grooved pavement, avoid straight rib tires, they'll put you in the hospital or a coffin.