I didn't even notice the typo !
There was a very short-lived product with the "1757" bulletin number, called the ProcessLogix. But it had different controller numbers and Honeywell-joint-venture software.
1756 controllers include the whole ControlLogix family, from the late-'90s-vintage 1756-L1 to the modern 1756-L8xE controllers.
1756-L6x are two generations old and make up a substantial portion of the installed base of ControlLogix.
The 1756-L6x controllers accept up to v20 firmware, and if I was handed one and told to commission a system with it, I would install RSLogix 5000 version 20.05 and the newest firmware for the controller(20.019 for the 1756-L63), and go from there.
There was a confusing compatibility issue having to do with security signatures in the first releases of v20.x, so jump past that by installing RSLogix 5000 v20.05 and not any of the earlier versions.