Factory Roof Anntena Holes?

[BRL]

I was told this 1969 Chevy truck was an ODG Bell Telephone Co. truck and most everything I've noticed on it indicates that is true.

When I got it 20 years ago, I removed the dome light and found an antenna wire coming from the roof area on down, but dead ended before going much further, so I just pulled it out.

But there are three plugs on the roof, and I just wondered if the factory or maybe a contractor would have done this modification?

Also has a plug hookup for I assume a trailer that I blocked with an repo rear bumper and still has traces of the ODG color located in various spots so I do believe this was a telephone truck as the seller indicated.

Sorry for the huge pics. but my Photobucket is messing with me today and I'm surprised I'm able to post any pictures at all.

Anyone know?