Yep, might as well change the powder with your own while you are at it.
Nothing wrong with reloading steel cases. Just be aware that they are much harder on your dies, don't last near as long as brass casings and bottleneck cartridges are prone to get stuck easier in your sizing die.
I have reloaded straight wall steel pistol cases with few issues. Some of them will crack after one firing, some of them after several. Just clean and inspect them as normal.
Your 54R steel cases are probably berdan primed, so just discard them after the first firing. Berdan primers are too much trouble to change out.
Don't be discouraged from "Mexican loading". Nothing wrong with it at all. In fact it is a great way to get good accurate ammo with little money, and the practice is as old as reloading itself.
And please post your results. I am always up to read range reports.