That PN is obsolete and likely a combo code to consolidate part numbers.
In the late '70's and onward Honda would create codes for older parts that were essentially identical.
That switch could be used in a several different bikes, not just 750's.
For example PN 35010-303-003 was superseded by 35010-315-017 which is the current PN for a couple of dozen bikes prior to '71.
That -007 PN may have been the European number, same number later rev.