Jeb,
Mine is a real Heinz 57. It is a 455 II. but the cylinder and barrel are now post WWII. Both are .452 caliber. The barrel shown in that picture was the original, but was bulged when I got it. I think I still have the .455 cylinder.
The present barrel is a Brazilian surplus replacement meant for their Model 37s. I got it unfired off of GB for $75.00.
The cylinder is cut for moon clips and bored for 45 Colt. The gun will fire .45 Colts, but ignition is "iffy".
I use 45 Winchester Mag brass loaded to Colt 45 pressures in moon clips. That puts the bullet right up to the forcing cone thus eliminating the bullet jump of 45 ACP and ARs. I can shoot ACPs and ARs in the gun too but accuracy suffers a bit.
Dave Keith (keith44special) who has posted in this thread did the barrel work on mine, but I'm not sure he is accepting work these days. He cut it down from a 5" and moved the sights.
As to cost, we did some tradin' here and there.. I think I came out ahead of the game.
The gun is parkerized, but that was done locally.