Grill Amateur Needing Some Help 10c Green

I picked up a lot of stamps and just came across this grill which has me confused. It is a Scott A27 10c Green (not is great shape). It definitely has a grill, and the available choices are D, Z, E or F. Mine looks to be 13 or 14 wide. I must assume 14 but better/more eyes/opinions may help. Is it 17 or 18 tall? The pics of the grilled back are full size, closer up, adjusted via lighting and computer tricks.

Not related to the grill, but it looks like a TAG variety we've previously discussed.

Txstamp - you are correct in that I some time ago asked about what TAG meant. This is a different stamp today, and yes, it is a tag variety too. Thanks for remembering!

It's an E grill.

Thanks Winston!