I'll try the union something like:
select distinct hs.name, hs.city, hs.state into new_hs.
union both tables w/ new hs_id.
then go back and match hs_a by hs.name, hs.city, hs.state and create a cross-ref table of old id to new id.
do the same with hs_b.
that may work. I'll see. There may be...