No, it was a 7070, "IBM seven oh seventy",
and it used hundreds if not
 thousands of 12au7s or 12ax7s don't remember which it was.  And it was
 definitely NOT solid state. 
I do not know if IBM made a 707, but I would bet that would be it.
The 7070s were made from solid state modules, probably using the SMS
packaging system.
  Maybe IBM used some numbers over?  But I am absolutely
sure of the number
 because we called it by that name when referring to it. 
Very rarely, and when it is done, the two instances are completely
different, like a modern RAID box and a paper tape reader.
--
Will