What are those extra tube inputs for?

Hi folks,
I have an amp built on a Dynaco st 70 chassie. It is only 8wpc and uses el34's. The guy who built it said the he used all platinum connections in it's guts and chrome plated it. Saying that the only Dynaco thing about it was the chassie. It has these extra tube input holes in the front coming out horizontally. I havent the slightest idea what they are for. Should I stick some extra tubes in there?