I don't expect too much problems but you really want to try it in a separate test game first to see if you really do not get any weird behavior.
Apart from that I don't really recommend it. There is no source available for that patch level any more, so even IF a developer would want to look at it, they can't do anything about it, furthermore I don't think there are many people who remember exactly what the ins and outs of that specific patch level/mod were. So should you have a question or problem, chances are slim you'll be able to get an answer.
ETA: Should you decide to patch, keep in mind just about the only option you have is bring your game to the latest patch level (1.67). In terms of NRaas mods that would be great as you'd be OK with all the latest developments, but if my memory serves me well there have been significant changes in the game itself between 1.57 and 1.67.