Hey guys, need some help here!

I am trying to replace the plenum gasket, but I'm trying to make it out of a ¼" aluminum plate that I have sitting here at the shop.

I have seen some plenum gaskets that have had this type of aluminum gasket installed.

I know the sell them, but I have the means of doing it in my shop and was wondering if any body has the hole locations so they can be machined into the plate?

I also have 3/16" thick and 1/8" thick alum plates big enough to make it. Is ¼" to much?

Any help would be appreciated...

thanks!