Two-prong plugs are listed in the NEMA receptacle configurations chart
as (straight blade receptacles) 2-pole 3-wire, grounding, 125 volt,
listed as 15 ampere (#6-15).  Nowadays there are only three listed
manufactured 2-wire plugs.

If you do not need the ground connection just do not wire it.  Also,
the male plugs will require a 3-hole receptacle.  You can remove the
ground prong but changing both sides would look nicer.

You should be able to find them at any larger electrical supply house.
Most will sell to people off the street for cash or credit cards.
A lot have the above-mentioned NEMA chart on their wall because most
electricians will go in and ask for a plug with 2 prongs, etc., and
draw a stick picture on the palm of their hands <lol!>.

For an old antique plug you will have to search the Web for a supplier
of vintage electrical parts.

Glen R. Perye Jr.