question on tires

[1970shortbed]

i went to the tire shop and got 4 wheels/tires and did not realize until i got back that one is a 6 lug and the other three are the uni lug type wheels with like 12 holes

now i have no problem with this other then the three with the 12 holes fit the bolt pattern with n/p but i still have drums on the back and they wont fit over the end of the axle

now should i just bring them back and get all 4 with just the 6 lug or is`there a way to make the center hole in the other 3 just a little bigger without ruining the wheels or compromising safety