SVT back cover removal tool

[mrbthree]

What kind of tool is used to remove the back cover/grill off a late 70's SVT head?
It's a 4-sided hole with 2 straight sides and 2 curved sides. I'm stumped.
Thanks

[Ronsonic]

You're looking for a clutch head screwdriver. It used to be common for some cars and trucks, worked great in power drivers.

[Jazz P Bass]

Fliptops

[Enzo]

I have bought clutchead drivers at Sears in the hardware. Check at any hardware store with a good selection of hand tools

And I am a big fan of the Xcelite 99 series tools - the yellow handles you stick the various screwdriver blades into. They make a couple sizes of clutchead blades for that series too.

If you are into magnetip screwdrivers, I have a couple sizes of clutchead bits for them too.

[g1]

So that's what they're called! I have one but have always thought of it as an "Ampeg screwdriver" as I've never seen those screws used anywhere else.
That being said I've found a green robertson (#1 square head) screwdriver always works for these.