try just walking in to your local auto supply and buying a 1/4" drive 1/4" - 12 point socket!
Darn new air cleaner I got for on the bike has 3 bolts that take this and I went everywhere, excluding Sears
This is one of those situations where you need some contacts at a nearby local garage. Stop by there and find out from one of the mechanics just what the weekly schedule is for the (Snap On ) truck to stop by their shop or (Mac Tools, etc.).
Arrange to be at the garage when he shows up and/or get his business card from the mechanic and you can get fixed up with most any such tool.
I got frustrated a few years ago with trying to use cheap azz (made in China) snap ring pliers.

I caught up with the Snap On driver and got a whole set of snap ring pliers (internal/external) that work. Problem solved.