Ok, here is a real answer. A while back, a thread about a scamming ebay seller got crazy about showing pictures of penis and rare versions of Zelda. The truth is, this game is hardly worth more than $20.
As for variants and your copy with 3 screws and flat head screws, not worth much that I know of. Interesting, but not rare. Also, someone could just take flat head screws out of a gumshoe cart and stuff them into your Zelda. So it defeats purpose.
This thread did make a few of us laugh (including me) at your expense. But thanks for being a good sport and catching on before we got to out of control again
If you search "Zelda Appraised" you'll probably find the thread that started this whole thing. It's a funny read.