Rear Drum 1968 bay bus. Help!

Hi all,

Question:

Why does nobody make a new back plate for 68 bays?

Question 2:

If someone does, where and how much?

Question 3:

If not where can I get a really good one so I can blast it clean?

Question 4: If not can I convert my rear brakes easily to a different year that is available?

Any help would be greatly appreciated

Larry