Cant say I have seen one. I would guess it was only used in
Chicago. Most Zenith was sold through independent distributors.
They sold sets, parts & had service depts. I doubt any had computers
til late. I suppose you could throw them in a box when a sleeve
ran low & when one of the indies salesmen comes weekly you
could hand them over. Other than that I think its just a "look what we
can do" type thing. I see no advantage over writing the number
on the want list.
73 Zeno
LFOD !