[Sonic character base avatar shop's in game location?]

Try searching for Lobster Cat Designs or Blades Sanctum. I remember getting av bases from one of those spots.

[Need a mature avatar]

I too bemoan the scarcity of average-bodied avatars. :catsad: For male avs, RUBY Skins might be your best bet:

https://marketplace.secondlife.com/stores/52352

[A sad day]

Gaming aficionado here

Four of those meshes (while mangled in places) were clearly ripped from The Legend of Zelda: Twilight Princess, a Nintendo Gamecube/Wii game. The blue girl is a character from another Zelda game, but it's no rip - compare it with an image of her in-game model: http://zelda.wikia.com/wiki/File:Fi.png

As for the bow, I don't recognise it, so it's either from another game or is original content for SL.

 

I only have a vague idea of what Nintendo's stance is on usage of their graphics, but (like most companies) they're more likely to act if money's being made. Your best bet for contacting them would be to look here: http://www.nintendo.com/corp/index.jsp