This is the first case I've heard of any normal player actually paying any attention to version numbers of a mod.
Honestly, if something like that bugs you that much, you're likely better off just not playing on this server. Yes, there are changes that are different from "official" prophunt versions, but there are other servers with such changes, too. Off the top of my head, SourceOP has a fairly different version running. If you want the most official prophunt you can get, GM is the place to be.
For what it's worth, SourceOP's prop hunt mod is a from-the-ground LUA rewrite of GM's prop hunt config from three years ago. It hasn't been updated as GM's has and in that sense is more original than the one we have here and even GM's itself as I don't think Dark maintains it anymore.
It is not bugging me or anything, I am just wondering what actually changed, because there are so many different versions yet I could barely make out any changes. In this case even none.
The version number changes every time ANYTHING is changed, such as banning new botkiller weapons or changing weapon damage around. Off the top of my head, the changes between this version and the one GM runs on are Reserve Shooter damage changed from 80% or 100% (depending on server) to either 25% or 50%, heavies taking damage on spin-up instead of shooting, crusader's crossbow unlocked with no healing effect on allies.
Keep in mind that I've played maybe 5 or 6 times in the past 5 or 6 months so I might have missed something.