Long overdue, today I finally made some new hood and battery box keys. Someone here asked about them months ago.
Bought the Craftsman 8mm sockets (P/N 33084) on eBay for about $2 a piece, and the so-called locomotive key for about $7.
The 10mm ratcheting wrenches were around $3 each on eBay, bought because I wanted a tool for bleeding the filters on board.
Anyway, the locomotive key didn't quite work out. It was easy enough to machine the square end so it fits a SEE hood, but the female end is too large, and being aluminum it can't easily be welded up, or to something that fits. Not by me, anyway.
Used some old rod and ground it to a reasonable facsimile of the factory key, then welded a socket to the other end and bent the rod. That means about $2 and 10 minutes to get an ugly but functional key instead of paying $26 for a nice looking one.
That's actually what got me started on this; I ordered two keys but only got one. Really needed two more but wasn't about to pay $52 plus shipping. Yes, I'm cheap.
Hopefully this can help you make your own version, keeping some money for parts that are hard to make and better bought.