[Hallicrafters] SX-28 Qustyion

[BSugarberg]

Hello,

I was looking at the back side of an SX-28 front panel,
and noticed just below the s-meter window a orange colored
1/2" square diamond-shaped box with the number 17 inside it.

Is this a Hallicrafters factory inspection stamp, or is this
some kind of military inspection stamp?

Thank you,

Bruce WA8TNC