Hex receivers are older, I'm sure someone will chime in with exact dates. Check out this site http://7.62x54r.net/
It's full of great info. And look at their Mosin Nagant humor page while your at it, you'll get a good laugh.
As far as sporterizing, I myself am not quite purist (I've stripped and stained my stock) but I really don't like the cutting and chopping and permanently changing the form. But like so many other things in this world (like say, abortion) No matter how much I hate it, I try not to control other peoples lives, or give them too much Hell and strife for what they've done.
Now I had a pawn shop try to sell me a bubba'd m44 for about $400. I threw a screaming fit, not because it was butchered, but because they were trying to pull a rip off.