Well, given that this is a one-off, what I'd do, after making a backup copy of table1, is the following:
select
t1.uniqueID
,t1.makecode
,t1.modelcode
,t1.body
,t1.date
,1 as matchID
,t2.completecode
into
matches
from
table1 t1 inner join table2 t2
on t1.cc = t2.cc
and...