It doesn't matter how many people want you to change a map unless the original author is among them.
Of course players won't care, because in their eyes you just fixed the map. Like you said, you just made invisible, surgical corrections to keep the maps alive like they arguably deserve. I totally get where you're coming from and that's why I'm just stating and explaining my position. I won't argue with you or try to convince you. I just want you to understand. You'll have to make up your own mind.
That's not how mappers who care about custom content see it though. What mappers do and create they create for nothing but a little recognition so while it would be anyone's right to sue someone who stole their content it's never worth the hassle. How much rights do you have over your map anyhow, if you used the engine and content from the game? How much damage was done if you never had the intention of selling your content, and even if you had you couldn't because of licensing issues with the game? It's always tricky and even if it wasn't, no one's ever going to court over something like this.
So the sad truth is, amateur modders have NO way of protecting their content. None whatsoever.
The only thing that helps us as a community of creators of content is if we abide by a strict code of honor. The only thing that can be stolen from us: recognition, has to be made impossible to steal. This means that if a modder is caught stealing content this stolen work must not earn him any recognition. On the contrary, exposing this violation of our code of honor must be punished by destroying that individual's reputation as a modder.
Only if we are very strict with these rules, and only if we take them as a principle can this work. If it's "ok" to steal content in this or that circumstance it would stop being seen as the horrible crime it must be seen as.
This all sounds much more samurai than it is. I'm not some vigilante nutjob. As you may know I expressly allowed use of content from my maps for everyone working on Killing Floor projects. I would probably allow you to fix my maps too if you ever contacted me. In my view, I created content for the community so the community can enjoy it (almost) however they please.
I do however recognize that not every feels like me and that the only protection against intellectual theft is to be strict about it.
I also see how this is a special case though. The maps would be forgotten because of ridiculous oversights and you fix them, thus saving them from undeserved death and you don't demand credit that isn't yours either, as far as I know.
Personally, I'm against what you do. In the few cases that a good map would die off AND the original mapper doesn't give you permission to change it (because that's how it must be seen! It's not "I can't reach him, but he'd probably be fine with it anyhow, I mean, why wouldn't he"! It's "I did not get permission to touch this map") I would maybe sad about it, but accept that there is nothing I can do. As unfortunate as it may be.
That's me though. Don't stop doing what you do on my account. And
please don't send anyone my way.
Just understand both sides of the argument and weigh up the need for us as a community to stay loyal to our collective ideals against the need to fix maps you're not allowed to touch.
Just, when you decide to fix them, try to do it as you claim you do and stick to fixing invisible exploit problems and make sure players understand who's map it really is!
Good luck either way.
